Asthma FAQs

Asthma is a disease that affects the breathing passages, or airways, of the lungs. Asthma is a chronic (ongoing, long-term) inflammatory disease that causes difficulty breathing.

When an exacerbation or "attack" of asthma takes place, the inflammation in the airways causes the lining of the breathing passages to swell. This swelling narrows the diameter of the airway, eventually to a point where it is hard to exchange enough air to breathe comfortably. This is when coughing, wheezing, and the sensation of distress start.

There are three "levels" of asthma.

• With mild asthma, symptoms occur no more than twice a week (with nighttime attacks no more than twice a month). The attacks don’t last long, and they are alleviated quickly with medication. There are no symptoms between attacks.
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• With moderate asthma, symptoms occur almost every day and require an inhaler almost every time an attack occurs for symptom relief.
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• With severe asthma, symptoms are present most of the day every day. They restrict activity, and they have often necessitated a hospital stay.

There are also several types of asthma.

• Adult-onset asthma develops after age 20. It is less common than asthma in children, and it affects more women than men.
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• Exercise-induced asthma involves symptoms that occur about 5-20 minutes after beginning an exercise that involves breathing through the mouth. Sports and games that require continuous activity or that are played in cold weather (for example, long-distance running, hockey, soccer, and cross-country skiing) are the most likely to trigger an asthma attack. Other physical exertions that can trigger an attack include laughing, crying, and hyperventilating.
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• Occupational asthma occurs in response to a trigger in the workplace. These triggers include contaminants and allergens in the air and extremes of temperature or humidity.
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• Nocturnal asthma occurs between midnight and 8 am. It is triggered by allergens in the home such as dust and pet dander or is caused by sinus conditions.

While there is no known specific cause of asthma, what all people with asthma have in common is chronic airway inflammation. Their airways are highly sensitive to various triggers. When their airways come into contact with a trigger, the airways become inflamed: they fill with mucus, swell, and narrow. Then muscles within the airways contract, causing even further narrowing of the airways. This makes breathing difficult and results in an asthma attack.

Triggers are different for different individuals. Common ones include the following:

• Exposure to tobacco smoke
  
  
• Breathing polluted air
  
  
• Inhaling irritants such as perfume and cleaning products
  
  
• Allergens such as molds, dust, and animal dander
  
  
• Exposure to cold, dry weather
  
  
• Stress
  
  
• Exercise or physical exertion
  
  
• Medications including aspirin and nonsteroidal anti-inflammatory drugs, such as ibuprofen
  
  
• An upper respiratory infection such as a cold, flu, or bronchitis
  
  
• Sulfites (additives to some foods and wines)

Changes in weather can also trigger asthma attacks because of the irritants stirred up by wind and rain.

Asthma is on the rise in the United States and other developed countries. While the reasons are not clear, the following factors may contribute to the rise:

• Spending more time indoors where exposure to indoor allergens such as dust and mold is greater
  
  
• Living in cleaner conditions than people did in the past, which makes our immune systems more sensitive (reactive) to triggers
  
  

• Exposure to increased air pollution

• Increased physical inactivity (lack of exercise)
  
  

Asthma affects 17.3 million people in the United States (more than 6% of the United States population) and 130 million people worldwide. The number of people affected is 8-10 times higher in industrialized countries than in developing ones.

Children age 10 and younger account for 50% of asthma cases. In most children, asthma develops before they are age 5, and in more than half asthma develops before they are age 3.

More than twice as many boys than girls have asthma, although boys are more likely to experience a decrease in symptoms as they reach adolescence. In adult-onset asthma, the number is reversed. Twice as many women than men visit the emergency department and are admitted to the hospital with asthma.

Asthma affects all races worldwide but is more common in blacks and Hispanics.

Occupational asthma (asthma triggered at work by exposure to irritants present at the workplace) is most common in those who work with animals or animal-derived products and in industries such as plastics, rubber, chemical, textile, electronics, painting, printing, metalworking, baking, and gardening.

Risk factors for asthma include the following:

• Smoking or living with a smoker is a major risk factor. About 25% of children who have asthma have at least one parent who smokes.
  
  
• A family history of asthma. If one parent has asthma, a person has a 25% chance of developing it. If both parents have it, a person has a 50% chance of manifesting asthma.
  
  
• Having allergies, including hay fever and eczema. It is not known why some people have allergies and some don’t, but allergies can be inherited (although people don’t necessarily develop the same allergies as their parents have).
  
  
• Having allergies or severe viral infections before the age of 3
  
  
• Living in the inner city, especially in a low-income group
  
  
• Being exposed to mice and cockroach waste products
  
  
• Frequently being exposed to triggers

People with asthma react in different ways to risk factors and triggers. Some experience asthma symptoms when they are exposed to several factors or triggers at once, while for others exposure to one trigger alone is enough to set off an attack. Some people have more severe attacks when they are exposed to more than one trigger.

When people with asthma are exposed to their triggers, their immune systems start trying to fight off the allergens. This results in inflammation (swelling) of the walls or lining of the air passages that blocks or narrows the airways. This makes breathing difficult (like breathing through a straw for a long time) and noisy, and/or it causes coughing.

When breathing passages become irritated or infected, an asthma attack is triggered. Asthma attacks do not always occur immediately after someone is exposed to a trigger. Depending on the person and the particular trigger, an attack can happen hours or even days later. It may occur during either the day or night.

The main asthma symptom is wheezing. Wheezing is a whistling, hissing sound when breathing. This noise is made by the sound of air passing through narrowed tubes (air passages). Wheezes can occur during inhaling or exhaling but are usually heard while exhaling.

Other symptoms include breathlessness, chest tightness or pain, coughing, difficulty speaking, prolonged shortness of breath, and extreme fatigue.

Allergies and asthma are different, though they may have related reactions and some of the body's chemicals that are involved in allergies are also involved in asthma. An allergy is an inflammatory reaction or response to a specific substance. Allergic reactions can involve nasal membranes, the eyes, the skin, and the tongue, and the breathing passages in severe reactions. Allergy symptoms include an itchy, stuffy, or runny nose; sneezing; itchy, red, or irritated skin; and itchy, burning, or watery eyes.

Asthma is a chronic, inflammatory lung (lower respiratory) disease that causes difficulty breathing.

The things that trigger allergies can also trigger asthma attacks. Allergy symptoms may be a sign of irritants in the air that can provoke asthma symptoms, and allergy attacks can lead to asthma attacks. With both allergies and asthma, people’s immune systems react to fight off the allergens (the material that sets off the reaction). The resulting inflammation causes the airways in people with asthma to become significantly narrowed. The swelling that is called inflammation comes from increased mucus and an increased number of white blood cells in the walls of the air passages. In addition, the air passages are narrowed by the contraction of the muscle that surrounds the lining of the airways. These irritated muscles contract in excess, like a rubber band that closes the air tubes even further.

People with asthma also usually have allergies. About 80% of asthma in children and 50% of asthma in adults is felt to be related to allergies.

• Five thousand people die each year from asthma.
  
  
• Each year, asthma is responsible for 1.5 million emergency department visits, 500,000 hospital admissions, and 100 million days of restricted activity.
  
  
• In lost work and productivity, asthma is responsible for approximately $13 billion each year.
  
  
• Asthma accounts for more school absences and more hospitalizations of children than any other chronic illness.

If someone has had symptoms of asthma, talking with a doctor is important. A doctor will ask questions about that person’s symptoms, medical history, and medications.

The doctor will also perform breathing tests or blood tests to search for and rule out other causes of the symptoms (not all wheezing is asthma). A chest x-ray may also be taken to rule out other conditions that can cause similar symptoms.

If a person does have asthma, he or she will need to work out an action plan with the doctor in order to be prepared for an asthma attack.

Anyone who feels acutely short of breath or feels that he or she may be in respiratory distress should immediately seek care in an emergency department. This is also true for people with asthma who feel their symptoms are worse than usual or are not responding to usual treatment.

Asthma symptoms and attacks can improve with treatment or with time, but the asthma as a disease is not curable. Treatment can go on for a long time, and some people have to use medication for the rest of their lives.

Approximately half of children diagnosed with asthma outgrow their disease by late adolescence or early adulthood and require no further treatment. In some of these individuals, however, exposure to major respiratory irritants (such as smoking, massive exposure to fumes, etc.) later in life may trigger asthma symptoms once again.

Patients who do not control their asthma usually develop more severe asthma over time.

There are two types of asthma medications.

• Controller medications are for long-term control of persistent asthma. They help reduce the inflammation in the lungs that is behind asthma attacks. Controller medications should be taken every day whether someone is having symptoms or not. Controller medications include inhaled corticosteroids (the main type of medication), leukotriene inhibitors, methylxanthines, and cromolyn sodium.
  
  
• Rescue medications are taken after an asthma attack has begun. They stop the attack. Rescue medications include beta-agonists and anticholinergics, as well as systemic (pills or injectable) corticosteroids.

Knowing which medication is which is very important because a controller medication will not give immediate relief if someone is having an asthma attack.

Controller medications should not be stopped just because a person feels fine and has not had an asthma attack for a while. Feeling fine usually means that the controller is working to keep airways free from inflammation. Also, if a controller medication is stopped and a person starts experiencing asthma symptoms again, those symptoms are harder to control. If the controller medication seems to have stopped symptoms, a person can talk to his or her doctor about changing the dose or medication.

Talking with a doctor about possible side effects is important.

For some people, allergy shots can help control asthma symptoms.

For more complete information on medications, visit Understanding Asthma Medications.

For both controller and rescue inhaler medications to be effective, they need to be properly administered so that the medication can reach the deeper parts of the lungs where they are needed. It is important to receive teaching from a health care provider in the correct use of hand-held inhaler devices.

While asthma attacks may not always be able to be prevented, asthma can be managed.

• Avoiding triggers as much as possible is the best way to prevent asthma attacks (for example, eliminating pollen, dust, and mold from a home).
  
  
• Exposure to pets when children are very young may lower the risk of developing asthma. Children who live with two or more pets are less likely to react to allergens. If, however, an individual is already allergic to pets, it may be important to avoid exposure to that particular trigger.
  
  
• Taking medications as directed is essential.
  
  
• People who have outdoor allergies should avoid outside activities when the pollen count or pollution index is high.
  
  
• For exercise-induced asthma, several things can help. Spending time warming up before starting strenuous activity and gradually cooling down afterward, avoiding activity during a respiratory tract infection, and avoiding exertion in extremely cold weather may help prevent an asthma attack.
  
  
• Yoga may help manage asthma. Sahaja yoga is a type of meditation based on yoga principals that was found to be somewhat effective in managing moderate-to-severe asthma.

American College of Allergy, Asthma & Immunology
85 West Algonquin Road
Suite 550
Arlington Heights, IL 60005

American Academy of Asthma, Allergy, and Immunology
611 East Wells Street
Milwaukee, WI  53202
(800) 822-2762

American Lung Association
61 Broadway
6^th floor
New York, NY 10006
(212) 315-8700

Asthma & Allergy Foundation of America
1233 20th Street NW
Suite 402
Washington, DC 20036
(800) 7-ASTHMA

Asthma Society of Canada
130 Bridgeland Avenue
Suite 425
Toronto, Ontario M6A 1Z4
(866) 787-4050

Centers for Disease Control and Prevention/
National Center for Environmental Health
(888) 232-6789

National Institute of Allergy and Infectious Diseases
6610 Rockledge Drive, MSC 6612
Bethesda, MD 20892
(301) 496-5717

National Heart Lung and Blood Institute
PO Box 30105
Bethesda, MD 20824
(301) 592-8573

|Web Links|

American College of Allergy, Asthma & Immunology

American Academy of Allergy, Asthma & Immunology

American Lung Association

Asthma & Allergy Foundation of America

Asthma Society of Canada

Centers for Disease Control and Prevention/National Center for Environmental Health

National Institute of Allergy and Infectious Diseases

National Heart, Lung, and Blood Institute

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Author: Irina Petrache, MD, Instructor, Department of Medicine, Division of Pulmonary and Critical Care, Johns Hopkins University.

Coauthor(s): Amy Bremers, Medical Writer, .com, Inc.

Editors: Ryland P Byrd Jr, MD, Chief of Pulmonary Medicine, Medical Director of Respiratory Therapy, Quillen VA Medical Center; Professor, Department of Internal Medicine, Division of Pulmonary Diseases and Critical Care Medicine, James H Quillen College of Medicine, East Tennessee State University; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, ; Zab Mosenifar, MD, Director, Division of Pulmonary and Critical Care Medicine, Executive Vice Chair, Department of Medicine, Cedars Sinai Medical Center, Professor of Medicine, University of California at Los Angeles School of Medicine.