part 1:what is asthma? - science...

Healthy breathing

Healthy breathing is effortless. Aperson who is breathing normallywill not be aware of the process.Every minute of every day, thelungs expand and contract 15times. This process allows theblood to deliver oxygen to redblood cells and to take away car-bon dioxide.

Air enters the nose, where it iswarmed and moistened. Then, itenters the trachea, a single tubethat is the beginning point of theairways. The trachea divides intotwo narrower tubes calledbronchi. Each bronchus is a wayinto the lungs. As the air travelsthrough the lungs, it movesthrough progressively smallertubes called bronchioles. At thetip of the last bronchiole it enters,the air comes into contact withhundreds of millions of tiny airsacs called alveoli. These sacstake in oxygen from the air in exchange for carbon dioxide.Eventually, the lungs will exhalethe carbon dioxide.

For the exchange of oxygen forcarbon dioxide to take place, thediaphragm, a sheet of musclethat separates the chest from theabdominal cavity, must contract.When the diaphragm contracts, a partial-vacuum effect occursaround the lungs, causing them

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Part 1: What Is Asthma?

A s t h m a a n d A l l e r g i e s : T h e S c i e n c e I n s i d e

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to expand. When the lungsexpand, air pressure in the chestcavity is lower than the air pres-sure outside. This difference inpressure causes air from the outside to fill the lungs. Each time this happens, approximately 1 pint of air enters the lungs.

When you exhale, the diaphragmrelaxes. When the lungs deflate,carbon dioxide is forced out. Whilethis entire process is taking place,mucus in the air passages is trap-ping any foreign materials thathave entered your body with theair. After the mucus traps these

particles, the mucus is carriedby cilia (which look like tinyhairs) from the bottom of thelungs to the throat. Once themucus reaches the throat, it iseither swallowed or coughedout. If the mucus is not cleared,viruses, bacteria, and otherimpurities can collect in thelungs and cause infection or ill-ness. Healthy lungs are grayishpink in color. Lungs that aredamaged by pollutants canbecome blackened.

If your breathing is not healthyor normal, it might be due toallergies or even asthma.Allergies have been linked toasthma, so it is not unusual to find that a person suffersfrom both. These disorders can be treated, and sometimesthe symptoms can even be

prevented. With proper medicalcare and changes in behavior orenvironment, someone who suffersfrom allergies or asthma canbreathe comfortably and live an active life.

Problems associated with asthma

Asthma is a chronic lung diseasethat makes breathing difficult. Foran asthmatic, breathing becomesdifficult for a variety of reasons.Airways can become inflamed,restricted, or blocked, so that very

In an asthmatic person, themuscles of the bronchialtubes tighten and thicken,and the air passagesbecome inflamed and filledwith mucus, making it difficult for air to move.

In a nonasthmatic person,the muscles around thebronchial tubes are relaxedand the tissue thin, allowingfor easy airflow.

little air can travel to and fromthe lungs. The air that does getthrough these narrowed passagescan cause a high-pitched orwhistling sound called wheezing.The chest can also become tightor constricted, requiring the per-son to use more effort just tobreathe. This is called laboredbreathing.

If a lot of viscous (thick) mucus isreleased in the airways, it canproduce coughing. As the bodytries to clear the mucus from theairways, a rattling sound oftenoccurs. If the airways becomeplugged with mucus, the lungscan fully or partially collapse.This collapse can be caused by a number of conditions, from prolonged bed rest to pneumonia,and can be seen on a chest X ray.Unfortunately, when a collapsinglung is found—especially in com-bination with a rattling soundheard in the chest—asthma canbe misdiagnosed as bronchitis oreven pneumonia. Antibiotics areoften prescribed for bronchitisand pneumonia, but these med-ications are not effective againstasthma.

The symptoms of asthmaPeople with asthma experiencesymptoms that can include cough-ing, wheezing, congestion, andtightness in the chest. Most of

these symptoms are usually associated with colds or infec-tions. That is why it is importantto notice when they reoccur for no apparent reason. When thishappens, it could mean that youhave asthma. Although asthmasymptoms might resemble coldsymptoms, they must be treated differently.

A viral infection,such as a cold, mightmake it hard tosleep at night for afew days. Nighttimeasthma is very dif-ferent. It can makegetting proper restnearly impossible fora long period oftime. Some asthmat-ics have symptomsevery night. Peoplewith nighttime asth-ma often have tosleep sitting uprightin order to breathe.If these symptomsare disregarded ascold symptoms, thenthey will not be treated properly.A serious lack of rest can havedangerous consequences, especial-ly for a developing child.

Symptoms of asthma are usuallymeasured by their severity, fre-quency, and response to treat-ment. The National Institutes of

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Health has defined the followingseverity levels for asthma: mildintermittent, mild persistent,moderate persistent, and severepersistent. Those with the milderform of the disease might havebrief episodes once a week.Asthmatics with the most severeform of the condition have symp-toms that won’t go away, attacksthat easily become crises, very lit-tle lung capacity, and restrictedphysical activity.

Whether symptoms appear to bemild or severe, it is crucial thatthey be evaluated. Even if youseem to experience symptoms onlyafter exercise or during the night,an examination by a physiciancan be the first step in gettingrelief. For someone who has livedwith the symptoms for a longtime, the chest tightness andbreathing difficulty can seem

almost normal. Having problemswith breathing, however, is nevernormal or healthy.

Even some less common symp-toms of asthma require emer-gency help. If an asthmatic sud-denly starts to sweat, seemslethargic (or dazed), appearsfatigued, or has difficulty speak-ing, he or she should be taken toan emergency room. If the personhas severe difficulty breathing,intense coughing, a racing pulse,or cyanosis (nail beds or lips thatare bluish in color), these are alsosigns of an emergency.

The causes of asthma

Scientists still do not know exactly what causes asthma.Researchers are investigating anumber of possibilities, including

Severity Levels for Asthma

MILD INTERMITTENT—About half of all asthma patients fall into this category, which ischaracterized by fewer than two or three asthmatic episodes per week and no difficultysleeping at night. No continuous control treatment is necessary.

MILD PERSISTENT—Patients typically have tightness and wheezing weekly, but relativelynormal lung function overall. One controlling medication is sufficient to manage the illness.

MODERATE PERSISTENT—Daily episodes characterize this stage, but the flare-ups are manageable with two medications.

SEVERE PERSISTENT—Episodes occur daily, despite therapy with more than two controllingmedications.

(Adapted from http://www.nih.gov/news/NIH-Record/03_04_2003/story06.htm)

smog, lack of exercise, obesity, toomuch exposure to indoor aller-gens, and even a lack of exposureto viruses and bacteria in child-hood, which could weaken theimmune system. It is likely that anumber of factors combine tocause asthma.

Scientists do know that manypeople with asthma also haveallergies, such as hay fever oreczema, or a family history ofallergies. Others, however, haveno history of allergies or evidenceof allergic problems. Asthma alsoseems to run in families. If oneparent has asthma, his or herchildren are more likely to haveasthma. If both parents haveasthma, there is a 40% chancethat their children will developthe disease. Although severalpeople in the same family mayhave asthma, the severity of theirsymptoms may not be the same.Even if identical twins have asth-ma, one twin might have a moresevere case of it. Scientists do notknow why this is so.

Although the exact causes ofasthma may not be known, scien-tists do know a great deal aboutwhat happens inside the bodywhen an asthma attack occurs.Specifically, three changes occurinside the airways in the lungs ofpeople with asthma. The firstchange is inflammation (orswelling), which leads to constric-tion and sensitivity.

Airway inflammation happenswhen the mucosa (or bronchialmucous membrane) swells. Theinflamed tissues make a thickmucus, which is difficult to getrid of and can often producecoughing. This inflammation then


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Many childrenwho have asthma comefrom families in which their relatives alsohave asthma.

This illustrationshows the effectsasthma has on abronchiole. (left)Normal bronchi-ole; (middle) mus-cular rings con-tract and thicken,decreasing lumensize; (right)mucosal layersand their connec-tive tissue, thesubmucosa, thick-en, further closingthe lumen, whichfills with thick-ened mucus.

lumen

mucosa

muscular rings

lumen

submucosa

mucosa

leads to bronchoconstriction(or bronchospasm), in which thesmooth muscle that surrounds theairways contracts too much, nar-rowing the airways and making itdifficult to breathe. In people withasthma, inflammation also leadsto sensitivity. This means that theairways are overly sensitive (orhyperresponsive) to even minorirritants. Such irritants caninclude tobacco smoke, air pollu-tion, the common cold, or even coldair. If an asthmatic also has aller-gies, he or she can be overly sensi-tive to pollen, animal dander, ordust, for example.

Asthma can be triggered by bothallergic and nonallergic reactionsto various factors. Most asthmaattacks are of the allergic variety,resulting from exposure to triggerssuch as animal dander and mold.These triggers exist in both indoorand outdoor environments. Anasthma attack can result fromhigh levels of pollen in the air orfrom cockroach droppings inhousehold dust. A simple allergyskin test can help determine someof the triggers that cause thesymptoms. (For additional infor-mation on triggers, see the section“Causes of Allergies” on page 22.)

Nonallergic asthma can be trig-gered by exposure to viral infec-tions, shifts in air temperature,physical exertion, chemicals, med-


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What Causes Occupational Asthma?

Direct exposure to irritants. Substances such ashydrochloric acid, sulfur dioxide, and ammonia can trig-ger occupational asthma in those exposed to them.Commonly used in the petroleum and chemical indus-tries, these irritants are particularly harmful to peoplewith a history of respiratory disorders.

Allergic reactions from long-term exposure. A worker’simmune system might take months or years beforedeveloping a reaction to a particular substance, but thesymptoms can be quite severe. Everyday, common sub-stances can trigger symptoms. A veterinarian can devel-op occupational asthma from exposure to animal pro-teins. A health care worker can suffer from asthmasymptoms in reaction to the powder that lines latexgloves.

Accumulation in the body. Over time, workers whoinhale certain substances can experience asthma symp-toms because of a buildup of naturally occurring chemi-cals in their bodies. For example, an insecticide that isused in farming can cause acetylcholine to build up in a farm worker’s body. This buildup can cause airwaymuscles to contract, resulting in an asthma attack.

ications, or foods. Viral infectionscan bring on asthma especially inyoung children. When someonecatches a cold, the nose, airways,throat, and lungs often feel irri-tated. This irritation can triggerasthma symptoms. A conditioncalled sinusitis—in which thehollow cavities located behind theeyes and nose get inflamed—cancause asthma. Sinusitis can bringon wheezing, headaches, cough-ing, sinus pressure or pain, andpostnasal drip. During an attackof sinusitis, excess mucus drainsinto the nose, throat, andbronchial tubes. This drainagecan trigger or aggravate asthma.

Gastroesophageal reflux dis-ease (GERD), a condition inwhich stomach acid flows upthrough the esophagus, affectsmany people who suffer fromasthma. The symptoms of GERDinclude severe heartburn, belch-ing, frequent coughing, hoarse-ness, and asthma at night, aswell as after meals and exercise.Some asthma symptoms arerelieved by medications pre-scribed for GERD.

Another type of nonallergic asth-ma is called exercise-inducedasthma. It is triggered by strenu-ous physical activity. Intense, pro-longed breathing through the

mouth can lead to coughing ortightness in the chest. Exercisingin cold, dry air can also makebreathing difficult.

Asthma symptoms that developbecause of exposure to fumes,gases, dust, or other substancesin the workplace are called occu-pational asthma. This type ofasthma can develop in an asth-matic or in someone with no his-tory of the condition. The symp-toms of occupational asthma cancontinue even after the worker isno longer exposed to the sub-stance that triggered the initialreaction. The symptoms caninclude a runny nose and eye irri-tation, as well as difficultybreathing. Occupational asthmasymptoms often grow worse asthe workweek progresses, get bet-ter over the weekend, and then


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resume when the person returns towork. Smoking can also worsensymptoms, as can being exposed tosecondhand smoke.

A worker can be exposed to triggersubstances for months or yearsbefore symptoms arise. Often, thesymptoms of occupational asthmaare misdiagnosed as bronchitis.This is dangerous because it canlead the worker to return to theenvironment that caused thesymptoms. Continued exposure totriggers can be quite harmful.Employees are not the only peoplewho can be affected by harmfulsubstances in the workplace.Asthma can also occur in peoplewho live near factories that releasetrigger substances into the envi-ronment. Leaving an asthma-inducing work environment within one to two years of the initial illness can reverse occupa-tional asthma. For workers withthe disease who smoke, researchshows that those who leave the

unhealthy work envi-ronment and quitsmoking are more like-ly to recover fully thanis a worker whochanges jobs, but con-tinues to smoke.

In developed countries,occupational asthmahas become the mostcommon form of work-

related lung disease. According tothe American Academy of Allergy,Asthma, and Immunology, up to15% of asthma cases that havebeen diagnosed in the UnitedStates have some connection tojob-related factors. In certainindustries, the rate of occupationalasthma is quite high. In somemanufacturing companies, expo-sure to particular chemicals need-ed for producing plastics and foamhas resulted in symptoms in 10%of exposed workers. Inhaling a sin-gle enzyme that is used to makewashing powder has triggeredasthma in 25% of exposed workers.In the printing industry, regularexposure to gum acacia, which isused in color printing, has pro-duced asthma symptoms in 50% of the workers exposed to it.

An asthmatic can also experiencean attack as a result of taking par-ticular medications. Some of themost common medications thattrigger asthma symptoms are


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Occupationalasthma is the

most commonform of work-

related lung disease in the United States.


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aspirin and nonsteroidal anti-inflammatory drugs (NSAIDs),such as ibuprofen. In fact, accord-ing to the American Academy ofAllergy, Asthma, and Immuno-logy, up to 19% of adult asthmat-ics have sensitivities to aspirin or NSAIDs. Medications calledbeta-blockers—which are takento address heart disease, highblood pressure, glaucoma, ormigraines—can prompt asthmaattacks as well.

In about 6–8% of children, certainfoods and food additives can bringon asthma symptoms. Some ofthe most common products thattrigger asthma attacks are milk,eggs, peanuts, tree nuts (forexample, walnuts or almonds),soy, wheat, fish, and shellfish.

It is important to note that anxiety alone cannot give some-

one asthma. However, emotionalfactors can make asthma symp-toms worse or attacks more fre-quent. For example, if a person isunder stress, he or she will proba-bly feel more fatigued. Thisfatigue can increase the numberof asthma symptoms or makethem more intense. An anxiousperson might be more likely tohyperventilate, which can worsenasthma symptoms.

How asthma affects the bodyIn general, if asthma symptomsare addressed early and managedconsistently, there is little risk of significant damage. Each asth-matic episode does take a toll on the body, so it is best to try to prevent symptoms whenever possible.

Breathing insmoky air from a fire can worsenasthma symptomsbecause smokecarries very smallparticles that canbuild up in yourlungs. If you haveasthma and livein an area wherewildfires are common, youshould talk toyour doctor abouta plan for smokydays.

When an asthma attack occurs, a person experiences more thanjust difficulty breathing. Theinflammation and obstruction ofthe airways, both of which com-monly occur during an asthmaattack, can be associated with per-manent changes in the body. Theairways can become permanentlynarrowed. Usually, airway obstruc-tion does not cause any seriousdamage to the lungs, heart, orother organs. However, severeasthma attacks can lead to perma-nent damage or even death.During such an episode, an asth-matic can lose consciousness orsuffer brain damage because toolittle oxygen reaches the brain.This is one of the reasons that it isvital to seek medical help as soonas possible when a severe asthmaattack occurs.

When people suffer from exercise-induced asthma, their symptomsoften appear after only brief peri-ods of activity. Their airways tendto be overly sensitive to suddenchanges in temperature andhumidity. When people exert them-selves, they often breathe cold, dry air in through the mouth. This does not allow the naturalwarming and humidifying action of the nose to take place. Peoplewith exercise-induced asthma tendto develop a reduced capacity toadd moisture and warmth to theair before it reaches the lungs.

In addition, they have more diffi-culty exercising in environmentswhere air pollution and pollen arecommon.

How asthma affects lifestyleAsthma affects daily life in manyways. Often, an asthmatic mustrestrict activities to avoid exposureto trigger substances and factors.An asthmatic must be cautiouswhen taking a new medication,tasting a new food, or entering anew environment. A person withchronic asthma must remember totake daily preventative medica-tions on time. When going out,many asthmatics must arm them-selves with “rescue” medicationsfor use in case of an attack.

Frequently changes must be madeto an asthmatic’s home or workenvironment to make breathingeasier. Sometimes, bedroom car-peting and drapes, which can behome to dust mites, should beremoved. If the parents of an asth-matic child smoke, they shouldquit. If a factory worker developsoccupational asthma from a sub-stance in his or her work area, theperson should change job locationsor professions.

For many people, a common cold is just a brief annoyance. For anasthmatic, this minor infection can produce asthma symptoms.


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Asthma and PregnancyStudies have shown that pregnancy can worsen asthmasymptoms, most often in the late second and early thirdtrimesters. During the last fourweeks of a pregnancy, womenfrequently report experiencingfewer symptoms. If asthma ismanaged properly throughout a pregnancy, a woman willrarely experience symptoms atthe time of labor and delivery.

One reason that asthma symptoms might worsen during pregnancy is connected toGERD. When the stomach becomes compacted to make room for a baby, heartburn and acid reflux can result, making asthma symptoms worse. Sinus infections, viral respiratory infections, and increased stress can also worsen asthma symptoms during pregnancy.

Asthma in pregnant women is treated in the same way that asthma is treated in others.What is most important is that it be treated. If it is not, there can be dangers for both themother and the child. When an asthmatic first discovers that she is pregnant, she shouldmake an appointment with her allergist or primary care physician to discuss treatment.Like any other asthmatic, a pregnant asthmatic should avoid any substances or factorsthat are known to trigger symptoms.

Sometimes a patient and a physician must weigh the risks of unmanaged asthma againstthe risks of taking medication during pregnancy. Generally, it is considered far moreimportant to control asthma symptoms. There are asthma medications that can be takensafely throughout pregnancy. Most inhaled medications are safe for pregnant women.Oral medications should be avoided unless absolutely necessary.

Generally, allergy shots are safe for a pregnant woman who was receiving them beforeconceiving. A woman should not start receiving allergy shots for the first time while pregnant. Sometimes, an allergist will lower the dosage in the shot to prevent an allergicreaction. These reactions are rare, but can be dangerous to a baby.

If a pregnant woman’s asthma is not managed properly, serious complications can result.If not enough oxygen reaches the mother’s blood, then not enough oxygen reaches thebaby’s blood. This deficiency can threaten the baby’s growth and survival. A developingbaby needs to receive a constant supply of oxygen. A baby born to a mother with unmanaged asthma can have a lower birth weight.

With some medicines, physicians are not sure whether asthma medications can be trans-ferred to a baby through breast milk. Medications such as theophylline, beta agonists,cromolyn sodium, and steroids do not seem to be dangerous to nursing babies. To man-age allergy symptoms, a nursing mother can safely use prescription antihistamines anddecongestants.


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Benefits of ExerciseExercise offers many physical and emotional benefits, especially for people who sufferfrom allergies or asthma. Exercise improves cardiovascular fitness, muscle strength, andstamina. Physical activity improves circulation throughout the body and one’s generalenergy level. As a result of increasing physical activity, the body uses oxygen more effi-ciently and the respiratory system strengthens. Exercise elevates the mood and reducesstress. For people with allergies or asthma, the physical benefits of exercise improve theirgeneral health. In particular, it can help them breathe easier because more blood andoxygen reach the lungs. Exercise can ease the stress and anxiety that are often associatedwith asthma attacks. People with asthma should talk with their doctor before beginninga new exercise program, particularly a strenuous one.

Influenza (the flu) can bring onmore severe symptoms for a per-son who suffers from asthma. It is very important for asthmatics toavoid exposure to these viruseswhenever possible. It is wise forasthmatics to get yearly flu vac-cines. If an asthmatic is exposed to a cold or the flu, rest and propernutrition can help to prevent thesymptoms from escalating to asthma.

Often, asthmatics have difficultywhen they exert themselves inways that require deep breathing.Sports such as soccer, basketball,

and long-distance running, whichdemand continuous exertion, aremore likely to trigger asthmasymptoms. By contrast, sports likewrestling, gymnastics, baseball,and surfing require brief bursts ofenergy, which do not seem toaggravate asthma as often. Thosewho suffer from exercise-inducedasthma are likely to find walking,slower-paced biking, hiking, anddownhill skiing easier than thepreceding sports. With treatmentand careful training, an asthmaticcan participate in almost anysport.


Racing to Victory overAsthma and Allergies

As a competitive swimmer, Tom Dolancouldn’t have designed a better body forhimself. At 6 feet, 6 inches tall, with armsthat seemed to stretch the width of a poollane, he wasn’t exactly a welcome sight tohis opponents.

But what no one could see was that insideDolan’s imposing physique was an athleticflaw: lungs plagued by severe asthma andallergies. At times during his training work-outs, Dolan would labor for breath and

even black out in the water. His college coach always kept an inhaler rightnext to the pool. But instead of quitting, Dolan kept training harder andswimming faster—until he made it to the U.S. Olympic team.

When he came home from the Olympics in Atlanta in 1996, it was with agold medal—and he landed on the covers of Sports Illustrated magazine anda Wheaties box. He went back in 2000 to Sydney, Australia, and this time hedid even better, capturing a gold and a silver.

“I had no superhuman qualities that helped me to overcome asthma, exceptthe fact that I had a big heart and wouldn’t allow myself to be beaten downby asthma,” says Dolan. He also possesses an iron will: When he broke hisarm at age 11, he wore a special foam cast and dragged his arm through thewater as he swam countless laps.

Dolan’s competitive spirit is legendary in his family. To get him to drink milkas a child, his father would simply pour two glasses and say, “Race you!”

But at times, asthma seemed like the one opponent that could really giveDolan trouble in the pool. Although doctors often prescribe swimming as anideal exercise for asthmatics (because the humidity and warmth of the watercan make breathing easier), it’s with the understanding that asthmatics willswim slow, steady laps. The level of training Dolan underwent to take on thetop swimmers in the world was so intense that some doctors worried that hecould risk his health.

15Dolan, continued on next page

“When I was in high school, a lot of doctors told me not to swim,” says Dolan,who took up the sport at age five because his older sister was a swimmer andhe wanted to beat her. “They were worried about all the chemicals in the poolaffecting my allergies and asthma. I really had the worst of both worlds interms of athletics. The harder and more intense my training was, the worse myasthma became. And in the fall, with tree mold, and the spring, with pollen,my symptoms got worse.”

When Dolan was in college, he found a doctor who specialized in asthma andwho put him on a carefully monitored treatment regime. That helped Dolan’ssymptoms immeasurably—as his row of gold and silver medals prove.

Dolan recently retired as a competitive swimmer and is now living inArlington, Virginia, while he interviews with various corporations and pre-pares for a second career as a businessman. It’s a sure bet he’ll be successful in whatever he does—and, in a strange way, Dolan says he owes some of hisconfidence to asthma.

“One of the most frustrating things for young people with asthma is thatthere are only so many things that are in your control. You can’t control theheat and humidity and the air quality,” Dolan says. “For an athlete in an elitepart of the game, we like to control everything. So asthma gave me a lot ofperspective on the fact that swimming is just a sport and there are a lot ofthings out there that are more important. For all the troubles asthma gaveme, it also gave me a lot on the other side to make me stronger.”


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Diagnosing and treatingasthmaWhen a physician completes anevaluation to determine whethera person has asthma, severaltests are done. In addition to aphysical exam, the physician willask questions about the person’sgeneral health and symptoms.

If the person is experiencingsymptoms at the time of theexamination, the physician willtry to rule out certain conditions.It is important to distinguishasthma from bronchitis andpneumonia, for example. Bothbronchitis and pneumonia arecaused by bacteria and can betreated with antibiotics. Butantibiotics do not work for asth-ma. It is equally important thatthe physician zero in on the spe-cific physiological causes of thesymptoms. That is, whichprocesses in the person’s body areproducing a cough or a wheeze?Different physiological causesoften respond to different treat-ments. For example, bronchocon-striction will require a differentform of treatment than airwayinflammation.

Even if it appears that no symp-toms are present at the time ofthe exam, pulmonary functiontests can detect even minorblockage or airway obstructions.These tests can help the physi-cian determine the cause of theobstruction, if there is one. Thephysician might also have thepatient perform breathing testsbefore and after exercise to recordany differences in breathingcapacity. These tests can be con-ducted either in a physician’soffice or outdoors and are impor-tant for a person who seems to besuffering from exercise-inducedasthma. 41

Part 4: How Can Asthma Be Treated and Prevented?

During officevisits, a doctoror nurse maytest a patient’sability tobreathe tohelp figure out if he or she has asthma.

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A spirometer measures the abili-ty of a person to breathe out airfrom the lungs. If, after exertion,the person shows at least a12–15% decrease in the volume ofair blown out in one second—called the forced expiratoryvalue (FEV 1)—exercise-inducedasthma could be the cause.Outdoors, a portable spirometercan be used.

A device called a peak flowmeter can also measure breathingcapacity. If a peak flow meter isused, a 15–20% decrease in thevolume of air blown out indicatesthat a patient is likely to have

exercise-induced asthma. Peakflow meters may also be used todetermine when more or a differ-ent medication is needed.

Parents can help a physician eval-uate whether their child suffersfrom asthma. Perhaps they havenoticed that their child tends towithdraw from activities thatrequire physical exertion. Maybetheir child tends to cough orwheeze late at night or during acertain time of the year. Theremight be specific times when theirchild’s breathing sounds heavy ornoisy. These can all be indicationsof asthma.

A doctor may want to use a spirometer totest how much air anasthmatic can exhale.

The computer that thespirometer is hookedup to draws a graph

to show whether thepatient exhales thesame amount eachtime (normal lung

function) or less each time (asthma

or another lung condition).

Just as each person’s triggersare different, the types andseverity of symptoms vary.

This is why it is vital that eachperson understands the goals oftreatment, the approach torelieving symptoms, and his orher responsibilities for maintain-ing good health. For youngerpatients, parental involvementin treatment is crucial. As chil-dren mature, they should begiven more responsibility fortheir own asthma care.

Each person’s asthma care planis unique. The person beingtreated should actively partici-pate in making decisions abouthis or her asthma care. The bestway to do this is to learn asmuch as possible about the dis-ease. Whatever the approach totreatment is, remember the fol-lowing guidelines:

• If any part of the therapy is noteffective, discontinue it underyour doctor’s guidance.

• Do what works, unless therisks of the treatment exceedthe benefits of it.

• The side effects of the treat-ment should not be worse thanthe symptoms of asthma.

• The asthma care plan shouldbe simple and easy to follow.(An example is shown inAppendix 1 on page 72.)


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The inhaler dispenses abronchodilaterdrug thatwidens the airways in the lungs.

Components for ManagingAsthmaIn its National Asthma Education andPrevention Program, the NationalInstitutes of Health outlined four maincomponents for managing asthma:

• Medical personnel should use objec-tive tools such as the peak flowmeter and the spirometer to assesshow severe a patient’s asthma is andthen monitor treatment accordingly.

• Patients should avoid or eliminateenvironmental factors (for example,secondhand smoke, certain foods,strenuous physical activity) that trig-ger asthma attacks.

• Patients should consult a physicianto obtain proper medications. Thegoals are to manage flare-ups in theshort term and to prevent airwayinflammation in the long term.

• The patient, the patient’s family,and health care providers shouldform a partnership to define andimplement the best treatment plan.


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Preventing and controllingasthmaIn trying to prevent or controlasthma attacks, it is important tokeep in mind certain overall goals:

1. Chronic symptoms such aswheezing and coughing must beminimized.

2. There should be access to dailytreatments that allow for nor-mal breathing most of the time.These are often called “con-troller medications,” such assteroid inhalers.

3. Every asthmatic should try tomaintain normal activity levels,which include exercise.

4. Symptoms should be treated assoon as they appear, in order to minimize emergency room visits and hospitalizations.These treatments are in addi-tion to controller medicationsand are often called “relievermedications,” such as albuterolinhalers.

It is never safe to withhold treat-ment. Asthma is not a conditionthat a person should hope to out-grow. Having trouble breathing isnot something that will get betteron its own. It is a symptom thatneeds to be treated. It is alwayssafer to assume that narrowingairways will not open on theirown. Mucus that blocks the pas-

sage of air to and from the lungswill not loosen on its own. If anasthmatic is under the care of aphysician, any changes—improve-ments or setbacks—will be notedand treatments adjusted.

Even someone with an active formof the disease could experiencebrief periods without symptoms,especially as a result of treatment.This does not mean that it is safeto stop using the medications. Theopposite is true. The medicationshave helped the person remainsymptom free. The best way toincrease the number of symptom-free days is to remain under thecare of a physician and followtreatment instructions.

Intervention (or “rescue”) meas-ures can be used to control andrelieve asthma symptoms oncethey start. Controller medications,also known as maintenance med-ications, can be used to preventasthma symptoms from occurring.Ideally, controller medications canlessen the need for rescue medica-tions. If some attacks can be pre-vented, then there will be fewersymptoms to control. Once anasthma attack starts, its severityusually can be controlled. Whethera person has mild or severe asth-ma, there are ways to manage thecondition. If asthma symptoms arenot managed properly, a mild casecan become severe and a severe


case can become fatal. Learn torecognize the warning signs thatan attack might be getting worse.These warning signs can be dif-ferent for each person.

Some asthma sufferers receivetreatment only in an emergencyroom. Unfortunately, due to thehigh costs of health care, thismay be a way for some people toafford treatment. But emergencycare is not the best way to treatasthma. An asthmatic needsongoing care from a physician,not just rescue measures. In addi-tion, if only the flare-ups aretreated, then controller medica-tion cannot work to preventfuture attacks. The symptomswill continue and will reach a crisis state before treatment issought, which is bad for the per-son’s overall health.

It is vital that an asthmatic usethe correct medication for his orher condition. It is also importantto use the medication as directed.Take the dosage that is pre-scribed—no more and no less.In some cases, medications needto be used daily, even on dayswhen there are no symptoms.Steroid inhalers, for example, prevent symptoms only if useddaily, as directed.

Many medications are effective in preventing and controllingasthma. Some of them are calledanti-inflammatories. They dowhat their name suggests: Theyreduce the swelling of the air-ways, so that more air can travelto and from the lungs. Inhaledmedications have the advantageof being administered directly tothe area that is inflamed or

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An asthmaticneeds ongoingcare from adoctor, not justemergencytreatment at a hospital.


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obstructed. There are severaldevices used to administer inhaledmedications. Many metered doseinhalers (MDIs) use a chemicalpropellant—usually a chlorofluoro-carbon (CFC)—to force medicationout of the inhaler. Pharmaceuticalcompanies are in the process ofdeveloping other MDIs with pro-pellants that, unlike CFCs, do notdamage the ozone layer. Two typesof inhaler that deliver medicationwithout using CFCs are rotaryinhalers and dry-powderinhalers.

A device called a nebulizer deliv-ers a fine liquid mist through amask that is placed over the noseand mouth or through a mouth-piece. These devices make inhalingmedication easier, especially forinfants, children, and those unableto use a standard inhaler. Somenebulizers are small and portable,have battery packs, and can beused for travel.

Using an inhaler can be difficult at first. An asthmatic should ask a health care provider to demon-strate how to use it properly.Often, it is a challenge to directinhaled medication to the lowerairways accurately; it tends to get sprayed onto the back of thethroat. A spacer—a device thatfits on the end of an inhaler andprovides a holding chamber andone-way valves—can help adminis-

ter inhaled medication withgreater accuracy. Never overuse an inhaler.

Inhaled medications often causefewer side effects than oral med-ications do. The side effects associ-ated with inhalers vary fromheadaches to hand tremors.Sometimes these side effects canimpair learning in children. Whena child has a headache, it can bedifficult to concentrate. Handtremors can influence a child’shandwriting. It is important thatboth teachers and parents beaware of these side effects andmake an effort to note any thatoccur. In many cases, the type ordosage of medication can beadjusted to prevent side effects.

People who suffer from exercise-induced asthma can benefit fromusing a reliever-type medication,such as a short-acting bronchodila-tor, 15 minutes before starting anactivity. In one study, this form ofinhaler was effective for up to 4–6hours after inhalation in 80–90%of patients. Albuterol, pirbuterol,and terbutaline are among themedications in this category. In addition to preventing attacks,these inhalers can relieve symp-toms after they start. A longer-act-ing inhaler can provide up to 12hours of relief. If a child with exer-cise-induced asthma uses a longer-acting inhaler before leaving for


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school in the morning, it is possi-ble that there will be no need foradditional medication during theday.

Warming up before exercise and warming down after doesmore than just stretch muscles.For those with exercise-inducedasthma, it is another way to helpprevent the chest tightness thatis caused by cold air suddenlybecoming warm in the lungs.

Each person should play an activerole in his or her asthma treat-ment plan. This is easy to do:

• Know your asthma care planand when to use your controllerand reliever medications.

• Learn both the brand names and generic names of the med-ications that are prescribed.

• Write down any side effects that result from taking thesemedications.

A young girl breathes into the face mask of a nebulizer to relieve her symp-toms of asthma. The nebulizer delivers a fine spray of an asthma drug into theface mask and then into the throat and bronchial tubes. The drug is usually abronchodilator, which reduces the constriction of the airways to the lungs thataccompanies an asthmatic attack. Nebulizers are often used to treat emergencyasthma attacks. Most patients find them easier to use than conventionalinhalers.


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• Report any changes in symptomsor triggers.

• Ask a health care provider anyquestion that arises, and shareany concerns.

Apart from medication, someadjustments can be made to bothindoor and outdoor environmentsto help prevent asthma attacks.According to the American LungAssociation, the best environmentto live in is smokefree. This isespecially important in homeswith children. In fact, researchshows that the children of smokersare twice as likely to have asthmaas the children of nonsmokers. Asa rule, it is best to avoid an envi-

ronment where secondhand smokeis common. Pregnant womenshould not smoke. Women who dosmoke during pregnancy can givebirth to babies who have narrowed airways.

There are many forms of indoorand outdoor pollution. Wheneverpossible, it is best to avoid all ofthem. Indoors, many children and adults are sensitive to aller-gens that are known to cause asth-ma. These allergens include every-thing from cockroach and dustmite droppings to pet dander andmold. Cockroaches can be con-trolled or eliminated by using safepesticides. Dust mites can be kept under control by doing sev-eral things regularly: Wash bed-ding in hot water (130ºF or high-er). Keep floors free of dust by vacuuming with a machine thathas a special filter. Avoid placingcarpets, rugs, drapes, and stuffed

Asthma MedicationsMedications that are often prescribed to treat asthma include the following:

Anti-inflammatories (cromolyn and nedocromil are nonsteroidal examples)—These medications reduce swelling in the airways and lungs. Anti-inflamma-tories are not as strong as inhaled corticosteroids, but they cause fewer sideeffects.

Corticosteroids—Available since 1948, these steroidal, anti-inflammatorymedications are prescribed in different forms. Creams can be applied to theskin to treat rashes. Inhalers are often recommended for asthmatics withdaily moderate or severe symptoms. Pills are prescribed for those with severeasthma. Corticosteroids decrease swelling of the bronchial tubes, reduce theamount of mucus the body produces, and calm the airways. It is important to use these medications even on days when there are no symptoms, becausethey can help maintain healthy airways.

Bronchodilators (theophylline and anticholinergics)—Often called “rescue”medications, they open the bronchial tubes so that more air can travel toand from the lungs. These medications relieve coughing, wheezing, shortnessof breath, and difficulty breathing. They are available as inhalers, tablets,capsules, liquids, or injections. They shouls not be overused. If a patient usesmore than one canister (of an inhaler) a month, a new treatment planshould be considered. One exception is a long-acting medication—called salmeterol—which is designed for daily, preventative use.

Anti-leukotrienes—These are medications taken in pill form which fight the chemicals that cause airway inflammation and which make airways lesssensitive.


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animals in bedrooms. Irritantssuch as perfumes and strongcleaning agents or fragrances,which are found in many house-holds, should also be avoided.

Outdoors, high levels of pollenand mold can trigger asthmasymptoms in many people. Smokefrom factories and exhaust fromtrucks can also be harmful. Ondays when the air quality is con-sidered poor—often, days whenozone levels are high—doctorsmay tell patients to restrict physical activity or even to stayindoors.

Even for a person who suffersfrom occupational asthma, thereare treatments that can providesome relief. Special masks (respi-rators) can also be used to filterout allergens in the workplace.Many workers—from bakers tohairdressers—are exposed to sub-stances that trigger asthmasymptoms. After the trigger sub-stance is identified, it is impor-tant that the worker’s exposure toit be eliminated. If medications orrespirators don’t solve the prob-lem, the worker may have tomove to a location where the trig-ger substance is not present. If aworker is removed from exposurewithin 1–2 years of developingsymptoms, his or her asthma ismore likely to be reversible.Employers should monitor the

levels of these substances and tryto keep the levels low. Employerscan check for early signs of occu-pational asthma by testingemployees who are regularlyexposed to harmful substancesand ultimately can seek out non-harmful alternatives.

The relationship betweenallergies and asthmaScientists have long known thatthere is a connection betweenallergies and asthma. Many people who have one conditionwill develop the other. In fact,asthma is sometimes called anallergic disease. Both allergiesand asthma cause airway inflam-mation and narrowing of air pas-sages. In an asthmatic, this reac-tion might be caused by a respira-tory tract infection. In a personwith allergies, exposure to aninhaled allergen might cause thesame symptoms.

Allergic rhinitis (hay fever) is con-sidered a risk factor for developingasthma. According to the AmericanAcademy of Allergy, Asthma andImmunology, up to 78% of asth-matics also have allergic rhinitis.The symptoms of both conditionscan be triggered by allergens thatare either seasonal or year-round.Pollens, molds, animal dander, and dust mite and cockroach droppings are among the mostcommon trigger allergens. Somepeople have seasonal allergicasthma, a condition that occursover an extended period when high levels of allergens are common in a particular region of the country.

Many people who suffer from allergies will develop asthma.More than 50% of people who haveeczema will become asthmatic.People who have symptoms offood-dependent exercise-inducedanaphylaxis are often asthmaticsas well. Those with asthma,eczema, or allergic rhinitis are atgreater risk of having anaphylaxisat some point in their lives. Thissevere allergic reaction can occuras a result of exposure to foods,medications, latex, or insect stings.

The connection between allergiesand asthma can help physicians intreating both conditions. Forexample, the majority of asthmaattacks are triggered by allergicreactions. This means that if theallergic reactions can be controlled,the number of asthma attacks can be reduced. Many people with allergies are likely to developasthma. This means that a physi-cian should look for the early signs of asthma in such people and testtheir breathing capacity regularly.


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The Case of theUnusually HighAsthma Rates

Alexander Ortega has an inquisitive mind.Like a modern-day Sherlock Holmes, helikes to sift through facts and ponder difficult questions. A clue here, a trailpicked up there, and suddenly, the piecesof a tough puzzle all fall neatly into place. But Ortega isn’t a detective—he’s an assistant professor of epidemiology andpublic health at one of the country’s mostprestigious universities, Yale University inNew Haven, Connecticut.

Ortega’s work, however, involves seeing patterns that aren’t obvious tomost people. Right now, he’s trying to uncover the mystery behind thesky-high rates of asthma in Puerto Rican children.

Puerto Rican children have the highest asthma rates of children anywhere,with 30 percent of kids on the island suffering from the disease. Elevenpercent of children who are of Puerto Rican descent, but live in theUnited States, are also afflicted.

What Ortega wants to know—and hopes to find out—is whether thosekids are truly suffering from asthma or whether some of them have beenmisdiagnosed.

“There is a strong association between anxiety disorders in children andasthma—more specifically, to panic disorders and separation anxiety,” hesays. “The typical panic attack’s symptoms are identical to the symptomsof an asthma attack: shortness of breath, chest tightness, and wheezing.”

Could it be that thousands of children are really suffering panic attacks oranxiety, but are being treated for asthma? If that’s the case, Ortega wor-ries that the underlying mental health problems in a generation of chil-

Ortega, continued on next page

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dren aren’t being treated—and, like a domino effect, their mental health problems could worsen with time and affect their own children and families.

But that isn’t the only issue Ortega is trying to sort out. If, indeed, manyPuerto Rican children are suffering from anxieties and not asthma, thenwhy aren’t doctors identifying the real problem?

One reason could be that poor children don’t have equal access to qualitymedical care and that white children in general tend to get better treat-ment. “We know that Hispanic and black kids, particularly those who live inthe inner city and are poor and on Medicaid, are much more likely to beseen by residents or non-board-certified pediatricians,” Ortega reports. Onequestion he hopes to examine is whether doctors seem more willing toreport that a child has asthma if that child is black or Hispanic.

Ortega—who himself has seasonal allergies and “wheezes in April andMay”—says that many people, upon hearing of his work, assume that he is also Puerto Rican. “Actually, I’m Mexican-American,” he notes. Growingup, he crisscrossed the United States as a “military brat,” living in Honoluluand New Mexico before attending the University of New Mexico to studyeconomics and then the University of Michigan to receive his Ph.D. in epidemiology.

Ortega hopes to be on the move again soon: He is hoping to receive fund-ing for a grant that would allow him to focus on 1,000 kids on the island ofPuerto Rico in an intensive, three-year study. That will give him a chance tocollect more clues as he keeps digging into the complicated issue of thoseunusually high asthma rates.

part 1:what is asthma? - science...

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