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Breathing Easier

What is Asthma?

Child with Asthma
Pathology of Asthma

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Newborn Hearing Infographic Illustration: NIH, National Institute on Deafness and Other Communication Disorders

Fast Facts

  • Asthma is a chronic (long-term) lung disease that inflames and narrows the airways. The exact cause is unknown. There is no cure.
  • Asthma most often starts during childhood. Of the 24.6 million Americans affected, nearly seven million are children.
  • Asthma causes wheezing, chest tightness, shortness of breath, and coughing.
  • It's important to treat asthma symptoms when you first notice them. This helps prevent them from worsening and causing severe attacks that may require emergency care, and can be fatal.
  • Allergens, pollutants, and irritants can bring on symptoms. So can exercise, but do not avoid it. Physical activity is important for health. Discuss with your health professional asthma medicines that can help you stay active.
  • Most people who have asthma are able to manage the disease. They have few, if any, symptoms and can live normal, active lives.

Asthma is a lung disease that inflames and narrows the airways, causing wheezing, chest tightness, shortness of breath, and coughing. It starts mostly in childhood but affects all age groups. Asthma is a chronic—long-term—disease.


Airways are tubes that carry air into and out of your lungs. People with asthma have inflamed airways. They are swollen, very sensitive, and tend to react strongly to some inhaled substances.

When airways react, surrounding muscles tighten, airways narrow, and less air flows into the lungs. Swelling can worsen, making airways even narrower. There may be more mucus than normal, causing further narrowing.

This chain reaction can cause asthma symptoms. Sometimes, symptoms are mild and go away on their own or after treatment with medicine. Other times, they may get worse. If you have more symptoms or they get worse, you're having an asthma attack.

It's important to treat symptoms when they first appear to prevent them from getting worse and causing severe attacks. Severe attacks require emergency care and can be fatal.


Asthma can't be cured, but it can be controlled. With today's knowledge and treatments, most people who have asthma can manage the disease. They have few, if any, symptoms, live normal, active lives, and sleep through the night.

Successful treatment means managing your asthma actively every day and building strong partnerships with your doctor and other healthcare providers.

Common signs and symptoms of asthma include:

  • Coughing.
  • Wheezing.
  • Chest tightness, like something squeezing your chest.
  • Shortness of breath, feeling out of breath, or being unable to expel air from your lungs.

Not everyone with asthma has these symptoms. Nor does having them always mean asthma. To diagnose asthma for certain requires a lung function test, a medical history (including type and frequency of symptoms), and a physical exam.

Asthma symptoms vary in frequency and severity. Sometimes they may just annoy you. Other times they might limit your daily routine. Severe symptoms can be fatal, so it's important to treat symptoms when you first notice them, so they don't become severe. It is also important to take day-to-day actions to prevent symptoms from starting. Avoid things that bring on symptoms and take proper treatment. Many people benefit from daily medicine to control asthma and prevent attacks. With proper treatment, most people can expect to have few symptoms, if any, day or night.

Clinical Trials and Asthma

The National Heart, Lung, and Blood Institute (NHLBI) supports studies that explore:

  • How new technologies can improve asthma care
  • How certain medicines and other therapies can help treat asthma and improve quality of life
  • What factors cause asthma to develop

For more information about clinical trials related to asthma, talk with your doctor. You also can visit the following websites to learn more about clinical research and to search for clinical trials:

For more information about clinical trials for children, visit the NHLBI's Children and Clinical Studies Web page.

Fall 2013 Issue: Volume 8 Number 3 Page 12-13