What Is Asthma?

Asthma is a chronic lung disease that makes it harder to move air in and out of your lungs.

Key Points

  • Asthma is chronic. In other words, you live with it every day.
  • It can be serious, even life-threatening.
  • There is no cure for asthma, but it can be managed so you live a normal, healthy life.
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Asthma is a chronic lung disease causing changes in the airways of the lungs. Watch this 2-minute animated video to learn more about these changes and triggers that may cause symptoms leading to an asthma episode

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Speaker 1 (00:02): Asthma is a chronic lung disease that can cause breathing problems throughout someone's lifetime. When you have asthma, there is always a little swelling or inflammation inside the airways, with or without symptoms. Your lungs react to things that may not bother other people. These are known as triggers. Asthma can cause changes within the airway, all of which narrow the opening, making it difficult to breathe. A healthy airway is clear with no interior swelling, and the muscle bands around the airways are not tight. There is no extra mucus. Air moves freely through the open airway. When you have asthma, three main changes can happen in your lungs. If your asthma is left untreated or poorly controlled, changes to the structure of the airway may be permanent. One is swelling or inflammation. This is when the airway becomes swollen and irritated. When the airway becomes inflamed, it narrows and it is hard for air to flow through. Another change that can occur with asthma is extra mucus production, which clogs the airway, making the opening even smaller. The third change that can happen with asthma is the tightening of the muscles that surround your airways, called bronchoconstriction. This reduces the opening even more. When someone with asthma comes in contact with an asthma trigger such as dust, tobacco smoke, or even when laughing, any one or all three of the airway changes can happen. This is known as an asthma attack, or episode. All of these changes contribute to the narrowing of the airways, making it hard to breathe. Learn more at lung.org/asthma.

How Asthma Affects Your Body

With asthma, there is always a little bit of swelling inside the airways of your lungs. This makes the airways extra sensitive when exposed to viruses, allergens, irritants or even emotions. Learn more about how the air we breathe plays a role in our health.

Asthma Flare-Ups

During an asthma flare-up, the insides of your airways swell even more and can produce extra mucus. This narrows the space for the air to move in and out of the lungs. The muscles that wrap around your airways also can tighten, making breathing even harder. When that happens, it is called an asthma flare-up, asthma episode or asthma "attack."

After an asthma flare-up, you probably will feel tired. You're also at greater risk of having another flare-up for several days after an episode. For the days following a flare-up, be sure to:

  • Avoid your asthma triggers
  • Monitor your symptoms or check you airways using a peak flow meter

Airway Remodeling

Poor asthma management can lead to airway remodeling. Airway remodeling is a serious condition that happens when asthma is untreated or poorly managed. The lungs become scarred, asthma medicines do not work as well and less air is able to move through your airways. Airway remodeling does not have to happen. Work with a healthcare professional to minimize asthma flare-ups and find a treatment plan that works for you. Take control of your asthma.

Asthma can start at any age. Sometimes, people have asthma when they are very young and as their lungs develop, the symptoms go away, but it is possible that it will come back later in life. Sometimes people get asthma for the first time when they are older.

Reviewed and approved by the American Lung Association Scientific and Medical Editorial Review Panel.

Page last updated: April 19, 2023

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