Understanding Asthma -- the Basics

What Is Asthma?

Asthma is a chronic condition affecting the airways of the lungs. The hallmark symptoms of asthma are wheezing and difficulty breathing, but intermittent cough or chest tightness may be the only symptom. These respiratory symptoms usually come in episodes set off by various environmental or situational "triggers." Triggers include -- but aren't limited to -- chemicals, pollution, seasonal allergens like pollen and ragweed, animal dander, exercise, smoke, anxiety, and an upper respiratory virus like a cold. 

Most people with asthma have only mild and infrequent episodes. For them, the condition is an occasional inconvenience. For others, episodes can be frequent, serious, and even life-threatening if not properly treated. They may need emergency medical treatment. If you have asthma, have regular checkups by a doctor.

An asthma exacerbation (asthma attack) may pass quickly or last more than a day. Sometimes symptoms recur suddenly and with surprising intensity. This "second wave" attack can be more severe and dangerous than the initial episode and may last days or even weeks.

Asthma affects more than 23 million Americans of all ages, including more than 7 million children. Asthma is the leading cause of school absenteeism and pediatric hospital admission. Although asthma is seldom fatal, it is quite serious. If you have asthma, there are excellent (safe and effective) prescription medications to control it, so you should seek the help of a doctor before trying alternative therapies.

Asthma Myths and Facts

Myth: People with asthma shouldn't exercise.
Fact: Exercise is as important for people with asthma as it is for anyone else. With care or pretreatment, people with asthma can exercise normally and often vigorously. People with asthma generally do better with exercise in environments with relatively high humidity, since exercise-induced airway narrowing (bronchospasm) can be caused by drying of the airways. Slow warm-up and cool-down periods with exercise also helps to prevent exercise-induced bronchospasm (EIB).

Myth: You'll outgrow asthma.
Fact: This is both true and false. About half of the people who had asthma when they were between age 2 and 10 seem to "outgrow" the disease as they grow taller and notice a marked decrease in asthma symptoms. But in many cases, symptoms recur when they hit their 30s, start smoking, get a respiratory virus, or experience a large inhalant exposure. It's also common to develop asthma as an adult even if you did not have it as a child.


What Causes Asthma?

Asthma is usually not a problem with breathing in, but with breathing out. Asthma is a chronic illness with three main features:

  • Inflammation of the airways of the lungs
  • Constriction (bronchospasm or narrowing) of the airways (bronchioles) due to contraction of the muscles that surround the airways that is reversible
  • Extreme sensitivity of the airways to certain asthma triggers which cause them to quickly constrict, slowly become swollen, and secrete more mucus


Asthma and allergies are much more common in people with a family history of asthma or allergies. The factors which worsen asthma vary from individual to individual. Each person with asthma should seek to determine exactly which factors cause their asthma to worsen. Common asthma triggers include:

  • Allergies, such as allergies to house dust mites, cockroaches, cats, dogs, molds, mice, and grass, weed, and tree pollens
  • Infections, colds, influenza, and other respiratory viruses
  • Irritants, such as strong odors from perfumes or cleaning solutions, air pollution, and especially smoke from tobacco, incense, candles, or fires
  • Exercise, especially in dry or cold environments
  • Cold or dry weather and changes in temperature and/or humidity, such as with thunderstorms
  • Strong emotions, such as anxiety, laughter, or crying (which can cause heavy breathing)
  • Reflux of acid from the stomach (GERD)
  • Pain medications, such as aspirin or NSAIDs (10% of those with asthma are aspirin and NSAID sensitive)

WebMD Medical Reference Reviewed by Sabrina Felson, MD on February 08, 2017



National Asthma Education and Prevention Program. 

Expert Panel Report: Guidelines for the Diagnosis and Management of Asthma, 2002. 

National Institutes of Health publication number 02-5074, June, 2003. 

Brostoff J, Gamlin L. Asthma: The Complete Guide to Integrative Therapies. Healing Arts Press,1999. 

Plaut T, Jones T. "Dr. Tom Plaut's Asthma Guide for People of All Ages." Pedipress, Inc.; 1999. 

The Global Initiative for Asthma (GINA).


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