Have you ever seen a sunrise or a rainbow or a work of art so beautiful that it seemed to take your breath away? Such a “breathless” feeling is usually in your mind due to excitement.

For millions of Americans, though, breathlessness is a feeling they feel — physically — all too often, and it’s not at all enjoyable.

Asthma (pronounced az-muh) is a long-term disease of the lungs that causes inflammation and narrowing of the airways. When this happens, people may experience tightness in their chests, shortness of breath and coughing.

Asthma affects both the young and the old, although it usually starts in childhood. In the United States, doctors estimate more than 22 million people have asthma. Of these, about 6 million of them are children.

Your airways (also called your “breathing tubes” or “bronchial tubes”) carry oxygen from the air through the windpipe (also called the “trachea”) to your lungs. Many people take breathing for granted. It’s simply automatic.

For people with asthma, though, breathing can sometimes be difficult because their airways are very sensitive. No one knows for sure why some people’s airways are more sensitive than others’, but doctors do believe asthma tends to run in families.

So if you have asthma, you may have gotten it because of your family’s genetic history. It’s not like a cold, though.

Asthma is not contagious and can’t be “caught” through the air. You’re either born with sensitive airways, or you’re not.

People with asthma may breathe perfectly fine much of the time. Occasionally, though, asthma flare-ups — what some people call “asthma attacks” — occur and make it very hard to breathe.

During an asthma attack, the airways swell and get narrower, making it feel like you’re trying to breathe through a straw.

If an asthma attack is really bad, a person may need to use an inhaler to breathe medicine directly into the lungs. People who have frequent asthma attacks also may take medicine on a daily basis to help prevent attacks from happening.

Asthma attacks can be caused by a variety of factors, called “triggers.” Common triggers include allergens (such as dust mites, mold and pollen), animal fur, perfume, chalk dust, cigarette smoke, cold air, an infection or even exercise.

People who have asthma spend a lot of time learning what triggers they are most sensitive to. Once they learn what triggers their asthma, they can plan how to avoid these things and breathe easier in the meantime.

Unfortunately, asthma can’t be cured. Many children notice that their asthma goes away or gets better over time, though. Some doctors believe this is a result of their airways getting bigger over time.

Even for those people who continue to struggle with asthma, today’s medicines and treatments allow them to manage the disease in a way that lets them live normal, active lives. With the help of a doctor and an asthma management plan, it’s possible to breathe easy most of the time!