Shortness of Breath Symptoms, Causes and Risk Factors | American Lung Association

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Shortness of Breath Symptoms, Causes and Risk Factors

Shortness of Breath Symptoms You Shouldn't Ignore

Some people with respiratory problems can feel breathless just by doing normal activities like getting out of a chair or walking to another room. See your medical professional if your shortness of breath is accompanied by:

  • Swelling in your feet and ankles
  • Trouble breathing when you lie flat
  • High fever, chills, and cough
  • Lips or fingertips turning blue
  • Wheezing – abnormal whistling type sound when you breath in or out
  • Stridor - a high pitched noise that occurs with breathing
  • Worsening of pre-existing shortness of breath after using your inhalers
  • Breathlessness that does not go away after 30 minutes of rest

What Causes Shortness of Breath?

Most causes of shortness of breath are due to heart and lung conditions. Your heart and lungs are involved in transporting oxygen to your body and removing carbon dioxide, and problems with either of these processes affect your breathing.

Breathing is regulated by the brain and a complex interaction between various chemicals in the blood and in the air that we breathe. Oxygen levels, carbon dioxide levels, and the amount of hemoglobin in blood play a role. If blood carbon dioxide levels rise, the brain tells the body to increase the breathing rate, which can result in deeper or faster breaths. This may lead to a sensation of difficulty breathing. Likewise, too much acid in the blood from an infection, lactic acid build-up or other causes can lead to an increase in the breathing rate and the sensation of shortness of breath.

Causes of acute shortness of breath can include:

  • Asthma
  • Flare in COPD
  • Allergic reaction (such as bee stings)
  • Carbon monoxide poisoning
  • Heart attack
  • Low blood pressure
  • Pneumonia
  • Anemia (low red blood cell count)
  • Upper airway obstruction (blockage in your throat)
  • Heart failure
  • Enlarged heart
  • Abnormal heart beats
  • Choking
  • Foreign object inhaled into the lungs
  • Guillain-Barré Syndrome
  • Myasthenia gravis
  • Pulmonary embolism (blood clot in the lungs)

In the case of chronic shortness of breath, the condition is most often due to:

What are Risk Factors?

Having prior lung diseases, muscle weakness, low hemoglobin, being out of shape from lack of exercise or illness, severe obesity, and continued exposure to asthma triggers are some examples. Smoking is a major risk factor as it causes diseases that result in shortness of breath.

When to See Your Doctor

You should visit your doctor if you experience any shortness of breath that is not expected from an activity and the current state of your fitness or health. Breathing difficulty that comes on suddenly, is persistent or interferes with your daily activities should be evaluated by a medical professional. Shortness of breath that does not decrease with treatment or that is accompanied by other symptoms like chest pain needs urgent evaluation possibly in an emergency room type setting.

    This content was developed in partnership with the CHEST Foundation, the philanthropic arm of the American College of Chest Physicians.


    Approved by Scientific and Medical Editorial Review Panel. Last reviewed June 14, 2016.

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