What is Asthma?
Asthma is a chronic disease that affects the function and lining of the airways or tubes of the lungs. It narrows the airways and makes it difficult to breathe.
Asthma 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
- Cold weather
- 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
- Mold and mildew
- Smog or air pollution
- Perfumed products
Risk Factors for Asthma
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
- Tightness in the chest
- Trouble breathing
- Shortness of breath
- Chest pain
- Limited exercise tolerance, difficulty keeping up with peers
Diagnostic Testing for Asthma
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 exam—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
Asthma or Allergy?
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.
Content was created using EBSCO’s Health Library. Edits to original content made by Rector and Visitors of the University of Virginia. This information is not a substitute for professional medical advice.