Asthma and Allergybook pdf

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Part 1: What is Asthma?XXXXThe Science InsideAsthma and AllergiesHEALTHY PEOPLE LIBRARY PROJECTAmerican Association for the Advancement of ScienceAsthma andAllergies: TheScience InsideHEALTHY PEOPLE LIBRARY PROJECTAmerican Association for the Advancement of SciencePublished 2004 by The American Association for the Advancement of Science (AAAS)1200 New York Avenue, NWWashington, DC 20005© Copyright 2004 by AAAS0-87168-694-5All rights reserved. Permission to reproduce this document for not-for-profit educational purposes or for use in a review is hereby granted. No part of this bookmay be reproduced, stored in a retrieval system, or transmitted in any form, or by any means, electronic, mechanical, photocopy, recording, or otherwise, for commercialpurposes without prior permission of AAAS.This booklet is a product of the Healthy People 2010 Library Initiative funded by aScience Education Partnership Award (SEPA) from the National Center for ResearchResources at the National Institutes of Health (Grant # 5R25RR15601). Any interpretations and conclusions contained in this booklet are those of the authorsand do not represent the views of the AAAS Board of Directors, the Council of AAAS,its membership, or the National Institutes of Health. INTRODUCTION: ASTHMA AND ALLERGIES . . . . . . . . . . . . . . . . . . . . . 1PART 1: WHAT IS ASTHMA? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Healthy breathing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Problems associated with asthma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4The symptoms of asthma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5The causes of asthma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6How asthma affects the body . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11How asthma affects lifestyle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12PART 2: WHAT ARE ALLERGIES? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17Healthy immune system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17Problems associated with allergies . . . . . . . . . . . . . . . . . . . . . . . . . . . 19The symptoms of allergies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20The causes of allergies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22How allergies affect the body . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25How allergies affect lifestyle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26PART 3: WHO HAS ASTHMA AND ALLERGIES? . . . . . . . . . . . . . . . . . . 31Childhood allergies and asthma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31Uneven impact of allergies and asthma . . . . . . . . . . . . . . . . . . . . . . . 35Societal impact of allergies and asthma . . . . . . . . . . . . . . . . . . . . . . . 37PART 4: HOW CAN ASTHMA BE TREATED AND PREVENTED?. . . . . . . 41Diagnosing and treating asthma. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41Preventing and controlling asthma. . . . . . . . . . . . . . . . . . . . . . . . . . . 44The relationship between allergies and asthma . . . . . . . . . . . . . . . . . 49PART 5: HOW CAN ALLERGIES BE TREATED AND PREVENTED? . . . . . 53Diagnosing and treating allergies . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53Preventing and controlling allergies . . . . . . . . . . . . . . . . . . . . . . . . . . 57T ABLE OF CONTENTSPART 6: WHAT DOES RESEARCH TELL US ABOUT ASTHMA ANDALLERGIES? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61Current lines of research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61The important role of volunteers . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69CONCLUSION: Let’s Breathe Easy with Asthma and Allergies . . . . . . 71APPENDIX 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72Sample Asthma Action PlanAppendix 2: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75Questions to Ask Your Physician about Allergies and AsthmaAPPENDIX 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76Taking Part in Research Studies — Questions to AskRESOURCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79BIBLIOGRAPHY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83GLOSSARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 851Nothing is more essential toour well-being than the ability to breathe. Most of us breathe in and out all day long withouteven giving it a thought. Yet millions of people in the UnitedStates are not so lucky. They suffer from asthma or allergies.For people with asthma, taking abreath can be extremely difficult.For people with allergies, the airthey breathe can be filled withsubstances that cause discomfort or worse.Asthma is a chronic lung diseasein which air passages getinflamed. When this happens,airways narrow and it is difficultfor air to move from the nose andmouth to the lungs. In the UnitedStates, this disease affects mil-lions of people, many of themchildren. In fact, asthma is themost common chronic childhooddisease, affecting 1 out of every20 children. The number of peo-ple with asthma has beenincreasing since the 1980s. Thedisease affects people of all agesand races and both sexes.However, asthma is more com-mon in children than adults. It isalso more common in AfricanAmericans and Hispanics thanwhites.An asthmatic, or a person withasthma, responds differently tocertain substances than a personwho does not have the disease.For an asthmatic, these sub-stances become triggers. A trig-ger is a factor that can bring onthe symptoms of asthma or makethe condition worse. For an asth-matic, triggers can include house-hold or industrial chemicals,tobacco smoke, dust, changes inweather, and exercise. Exposed to a trigger, an asthmatic mightexperience tightness in the chest,coughing, wheezing, and short-ness of breath.Although asthma is common, it can be controlled and treated. It is important for an asthmatic INTRODUCTION: ASTHMA AND ALLERGIESAsthma affects 1 out of every 20 children.Asthma and Allergies: The Science Inside2to avoid contact with any triggerknown to cause symptoms. A per-son with asthma should get continuous medical care and see a physician regularly. A doctor can measure lung function andcapacity and recommend medica-tion to reverse and prevent airwayswelling and obstruction. If thesymptoms are managed well, anasthmatic can enjoy a normal life.Like asthma, allergies also affectmillions of people. An allergy isthe body’s overreaction tocertain substances, calledallergens. An allergic per-son responds differently toallergens than does a per-son with no allergies.Some of the most commonallergens include dustmites, cockroach drop-pings, animal dander,grass, insect venom fromstings, medications, andcertain foods. An allergicreaction can range fromsneezing and itching toswelling of the throat and loss ofconsciousness. As with asthma,allergic reactions can be severeand even fatal.A person with allergies shouldavoid allergens that are known tocause symptoms. People who haveexperienced severe allergic reac-tions should be under the care ofan allergist—a physician whospecializes in the treatment ofallergies. Before establishing atreatment program, an allergistwill conduct tests to determinewhich allergens are triggers for aparticular patient. The allergistmay recommend or prescribe med-ications that can reduce sensitivityto certain substances. Allergenimmunotherapy can also be usedto reduce sensitivity. A personundergoing allergen immunothera-py receives injections containingsmall amounts of the allergen towhich he or she reacts over thecourse of several years. This treatment helps the person build immunity to an allergen.Ultimately, this can mean that an allergic reaction does not occur at all.Fortunately, there are many prom-ising areas of research on allergiesand asthma. Scientists are work-ing to discover what causes asth-ma and allergies, how to preventthem from occurring, and how totreat them. But it is also vital thateveryone who suffers from asthmaor allergies have a basic under-standing of these ailments. Thisbook contains information thatwill help asthmatics and allergysufferers take charge of their ownhealth so that they can lead full,active lives.Healthy breathingHealthy 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 them3Part 1: What Is Asthma?Asthma and Allergies: The Science Inside4to 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 theseparticles, 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 asthmaAsthma 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 veryIn 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 ofthese 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 of5Part 1: What Is Asthma?[...]... doctor, proper medicine, and a healthy outlook, Huntley-Fenner has dealt with asthma head-on and instead of anxiously awaiting another attack, he has pushed it into the background of his busy, fulfilling life “I know that asthma poses certain risks for me and my family,” he says, “but I won’t let it overshadow my life.” 30 Part 3: Who Has Asthma and Allergies Childhood allergies and asthma It is estimated... common cold is just a brief annoyance For an asthmatic, this minor infection can produce asthma symptoms Part 1: What Is Asthma? Asthma and Pregnancy Studies have shown that pregnancy can worsen asthma symptoms, most often in the late second and early third trimesters During the last four weeks of a pregnancy, women frequently report experiencing fewer symptoms If asthma is managed properly throughout a... labor and delivery One reason that asthma symptoms might worsen during pregnancy is connected to GERD 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. .. buildup can cause airway muscles to contract, resulting in an asthma attack 8 Asthma can be triggered by both allergic and nonallergic reactions to various factors Most asthma attacks are of the allergic variety, resulting from exposure to triggers such as animal dander and mold These triggers exist in both indoor and outdoor environments An asthma attack can result from high levels of pollen in the air... from asthma, 5 million of them are children Childhood asthma is so common that it results in nearly 3 million visits to a physician and 200,000 hospitalizations each year Asthma often begins in early childhood Up to 80% of children with asthma show symptoms of the condition before the age of five The first signs of asthma in infants and children are often a cough, a fast or noisy breathing pattern, and. .. number of asthma symptoms or make them more intense An anxious person might be more likely to hyperventilate, which can worsen asthma symptoms In about 6–8% of children, certain foods and food additives can bring on asthma symptoms Some of the most common products that trigger asthma attacks are milk, eggs, peanuts, tree nuts (for example, walnuts or almonds), soy, wheat, fish, and shellfish How asthma. .. bring on more severe symptoms for a person who suffers from asthma It is very important for asthmatics to avoid exposure to these viruses whenever possible It is wise for asthmatics to get yearly flu vaccines If an asthmatic is exposed to a cold or the flu, rest and proper nutrition can help to prevent the symptoms from escalating to asthma Often, asthmatics have difficulty when they exert themselves in... as soccer, basketball, and long-distance running, which demand continuous exertion, are more likely to trigger asthma symptoms By contrast, sports like wrestling, gymnastics, baseball, and surfing require brief bursts of energy, which do not seem to aggravate asthma as often Those who suffer from exercise-induced asthma are likely to find walking, slower-paced biking, hiking, and downhill skiing easier... efficiently and the respiratory system strengthens Exercise elevates the mood and reduces stress For people with allergies or asthma, the physical benefits of exercise improve their general health In particular, it can help them breathe easier because more blood and oxygen reach the lungs Exercise can ease the stress and anxiety that are often associated with asthma attacks People with asthma should... training was, the worse my asthma 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 and who put him on a carefully monitored treatment regime That helped Dolan’s symptoms immeasurably—as his row of gold and silver medals prove Dolan recently retired as a competitive swimmer and is now living in . controlled and treated. It is important for an asthmatic INTRODUCTION: ASTHMA AND ALLERGIES Asthma affects 1 out of every 20 children. Asthma and Allergies:. For anasthmatic, this minor infection can produce asthma symptoms. Asthma and Allergies: The Science Inside12Part 1: What Is Asthma? 13 Asthma and PregnancyStudies
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