What Is Shortness of Breath (Dyspnea)?

If you're a healthy adult, you breathe in and out up to 20 times a minute. That's nearly 30,000 breaths a day. A vigorous workout or the common cold might throw a kink in that pattern from time to time, but generally you should never feel short of breath.

Shortness of breath, or dyspnea, can be a warning sign of a health problem that needs treatment right away.

If you have sudden, severe trouble catching your breath, call 911. This is especially true if you also have nausea or chest pain.


Dyspnea is the feeling that you can't catch your breath or get enough air in your lungs. You might feel:

  • Breathless
  • Tightness in your chest
  • "Hungry" for air (air hunger)
  • Unable to breathe deeply

It can be acute (sudden) or chronic (long-lasting). Acute dyspnea starts within a few minutes or hours. It can happen with other symptoms like a fever, rash, or cough. Chronic dyspnea can make you feel out of breath with everyday tasks, such as walking from room to room or standing up from a sitting position.

Sometimes, shortness of breath gets better or worse with certain body positions. For example, lying down flat can trigger shortness of breath in people who have certain types of heart and lung disease. Keeping track of your symptoms can help your doctor figure out what's wrong and recommend the best treatment.


Many health conditions can cause shortness of breath. The most common causes of acute dyspnea are:

Some of the more common causes of chronic dyspnea are:

Many other things, including panic attacks, lung cancer, and low red blood cell count (anemia), can make you feel out of breath. If you have dyspnea and don't know why, make an appointment with your doctor to find out.



Your doctor will examine you and listen carefully to your lungs. You might have a lung function test, called spirometry, to measure how much air you can blow in and out of your lungs and how fast you do it. This can help diagnose asthma and COPD.

Other tests you might have include:

  • Pulse oximetry -- a device is clipped to your finger or ear lobe, and a light on it measures how much oxygen is in your blood.
  • Blood tests, including a complete blood count (CBC) to see if you have anemia (when your body doesn't make enough red blood cells) or an infection and other tests to check for a blood clot or fluid in your lungs.
  • Chest X-ray or a computerized tomography (CT) scan to see if you have pneumonia, blood clot in your lung, or other lung disease. A CT scan puts several X-rays taken from different angles together to make a more complete picture.
  • Electrocardiogram (ECG) to measure the electrical signals from your heart to see if you're having a heart attack and find out how fast your heart is beating and if it has a healthy rhythm.


How it's treated will depend on the results of your tests and what's causing your shortness of breath. For example, if you have asthma, you may get an inhaler to use when you have a flare.

Living With Shortness of Breath

You often can build up your lung strength with exercise. Ask your doctor what activities are right for you. If you smoke, quit. Smoking is bad for your breathing and your overall health.

Shortness of breath is not a symptom to ignore. Always take your medications as directed and call your doctor if your symptoms change.

WebMD Medical Reference Reviewed by Jennifer Robinson, MD on May 15, 2019



UpToDate: "Patient education: Shortness of breath (dyspnea) (Beyond the Basics)." 

Wonderopolis: "How Many Breaths Do You Take Each Day?"

American Family Physician: "Shortness of Breath."

American Thoracic Society: "Breathlessness."

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