Asthma—Adult
Definition
Asthma is a chronic condition of the airways or tubes of the lungs. It narrows the airways and makes it difficult to breathe.
Inflamed Bronchus in the Lungs
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Causes
The exact cause of asthma is not clear. It may be caused by a combination of factors including environment, genetics, and biology.
Asthma symptoms are caused by an increased sensitivity of the airways to certain triggers. The triggers cause the lining of the airways to swell and produce extra fluid called mucus. At the same time, the muscles around the outside of the airway tighten in response to the irritation. All of these reactions narrow the airways and make it difficult to breathe. This response is often referred to as an asthma attack.
Possible triggers of an asthma attack in a person with asthma include:
- Viral illness
- Exercise
- Cold weather
- Sinusitis
- Gastroesophageal reflux disease (GERD)
- Sulfites used in dried fruits and wine
- Medications, such as aspirin, ibuprofen, and beta-blockers
-
Exposure to irritants or allergens, including:
- Cigarette smoke
- Smoke from a wood-burning stove
- Pet dander
- Dust
- Chemicals
- Mold and mildew
- Pollen
- Smog or air pollution
- Perfumed products
Risk Factors
Factors that may increase you risk for asthma include:
- Regularly breathing in cigarette smoke (including second-hand smoke)
- Regularly breathing in industrial or agricultural chemicals
- A family member who has asthma
- History of multiple respiratory infections during childhood
- Being overweight
- History of wheezing or asthma as a child
- Having allergies
- Your mother smoked during pregnancy
Symptoms
Symptoms include:
- Wheezing
- Tightness in the chest
- Trouble breathing
- Shortness of breath
- Cough
- Chest pain
- Limited exercise tolerance, difficulty keeping up with peers
Diagnosis
The doctor will ask about your symptoms and medical history. A physical exam will be done.
Your doctor may also do some tests to measure lung functions. They may include:
- Peak flow examination—blowing quickly and forcefully into a special instrument that measures your output of air
- Pulmonary function tests (PFTs)—breathing into a machine that records information about the function of your lungs
- Reversibility testing—tests for relief of airflow obstruction when medicines such as albuterol or ipratropium are given.
- Bronchoprovocation tests—lung function tests performed after exposure to methacholine to stimulate asthma; can help to confirm asthma in unclear cases
- Exhaled nitric oxide (a marker of airway inflammation)—to help monitor asthma control
Your doctor may also do some allergy tests. The test will help determine if allergies are causing symptoms. The test may include skin pricks or blood tests.
Treatment
The treatment strategy for asthma includes:
- Medications
- Avoidance of allergens and irritants and control of contributing factors (such as gastroesophageal reflux and sinusitis)
- Regular assessment and monitoring
You and your doctor should also create an asthma action plan. This is a plan you will follow to help control your asthma and handle asthma attacks.
Asthma Medications
Medications Used to Control Asthma
These medications are used to control the chronic swelling. It will help to avoid asthma attacks, but will not treat an existing attack:
- Inhaled corticosteroid—used daily to reduce inflammation in your airways
-
Long-acting beta agonists—(such as inhaled
salmeterol) used daily to prevent asthma attacks. In most cases, prescribed with an inhaled corticosteroid
- May increase the risk of asthma-related death, intubation (putting a tube in the windpipe to breath), and hospitalization—If you have any concerns, talk to your doctor.
- Cromolyn sodium or nedocromil sodium inhaler—used daily to prevent asthma flare-ups or to prevent exercise-induced symptoms
- Zafirlukast, zileuton, and montelukast—taken daily to help prevent asthma attacks
- Omalizumab (Xolair)—a monoclonal antibody against immunoglobulin E (IgE), given as an injection under the skin, used along with other medications for patients with harder to control asthma
- Theophylline—taken daily to help prevent asthma attacks, not as commonly used because of interactions with other drugs
Medications Used to Treat an Asthma Attack
These medications are used to treat an existing asthma attack:
- Quick-acting beta agonists—(such as inhaled albuterol, xopenex) relax your airways so that they become wider again, may also be used to avoid exercise-induced asthma attacks
- Anticholinergic agents—inhaled medications, such as ipratropium, that function as a bronchodilator, typically only used in an emergency setting
-
Corticosteroids—pills, injections, or IV medications given to treat acute flare-up of symptoms
- Pills may be taken for a longer period of time. They may also be recommended to help control asthma if you have severe asthma that isn't responding to other treatments.
Other Treatments
Prevention is an important step in asthma care. Allergy avoidance can be very effective with asthma that is exacerbated by allergens. Some general tips for allergen avoidance include:
- Avoid outside activities if there are high levels of air pollution, pollen, or mold spores.
- Keep your windows closed during seasons with high pollen or mold spores. Air conditioning may help filter out allergens during warm seasons.
- Consider getting a portable HEPA unit air cleaner to use in sleeping areas.
- Consider getting HEPA filters for your heating/cooling system and your vacuum cleaner.
- Have someone else vacuum for you. Avoid a room that has been freshly vacuumed. If you do vacuum, use a dust mask.
- Keep the humidity down in your house. This may help prevent the growth of mold.
- Treat allergies and sinusitis as recommended.
If allergies trigger your asthma attacks, ask your doctor about allergy shots. If you commonly have stuffy, runny, or itchy nose, these shots may improve your asthma.
In addition, it may be helpful to learn breathing techniques. Ask your doctor for recommendations.
Monitoring
Your asthma plan may need to be adjusted to adapt to changes in your life or health. Staying in contact with your doctor between visits can help you have better control of your asthma. Contact may occur over the phone, through email, or through your doctor's website.
Online programs aimed at helping you manage your own symptoms can improve asthma control and lung function. Some examples of programs include American Lung Association or Asthma and Allergy Foundation of America.
Prevention
There are no guidelines for preventing asthma because the cause is unknown. However, you can help prevent asthma attacks by avoiding things that trigger your attacks. Triggers can vary from person to person but some general guidelines include:
- Avoid strong chemicals or odors like perfume.
- Avoid strenuous outdoor exercise during days with high air pollution, a high pollen count, or a high ozone level.
- Get a yearly seasonal flu shot. Colds and flus can exacerbate asthma.
- Don't smoke. If you are pregnant, it is very important that you do not smoke.
- Avoid secondhand smoke. Do not allow anyone to smoke in your home.
- Don't use a wood-burning stove or fireplace, including unvented gas fireplaces.
- If cold weather triggers your asthma, avoid strenuous activities in cold weather. If you must, use a scarf or mask to warm the air before it reaches your lungs.
Talk to your doctor about:
- An appropriate level of exercise for you
- Ways to track your asthma to help identify and treat flare-ups right away.
- Your work, hobbies, and home activities to see if any of these may be causing or worsening your asthma.
RESOURCES:
American Academy of Allergy, Asthma, and Immunology
http://www.aaaai.org
American Lung Association
http://www.lungusa.org
Asthma and Allergy Foundation of America
http://www.aafa.org
CANADIAN RESOURCES:
The Canadian Lung Association
http://www.lung.ca
Allergy Asthma Information Association
http://aaia.ca
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Last reviewed September 2012 by Brian Randall, MD
Last Updated: 09/30/2012