Overview Of Fainting

Fainting is a brief loss of consciousness due to a drop in blood flow to the brain. The episode most often lasts less than a couple of minutes and you usually recover from it quickly. The medical name for this condition is syncope.

Commonly Associated With

Passed out; Lightheadedness – fainting; Syncope; Vasovagal episode

Causes Of Fainting

Fainting may occur while or after you:

  • Cough very hard
  • Have a bowel movement, especially if you are straining
  • Have been standing in one place for too long
  • Urinate

Fainting can also be related to:

  • Emotional distress
  • Fear
  • Severe pain

Other causes of fainting, some of which may be more serious, include:

  • Certain medicines, including those used for anxiety, depression, and high blood pressure. These medicines may cause a drop in blood pressure.
  • Drug or alcohol use.
  • Heart disease, such as abnormal heart rhythm or heart attack and stroke.
  • Rapid and deep breathing (hyperventilation).
  • Low blood sugar.
  • Seizures.
  • Sudden drop in blood pressure, such as from bleeding or being severely dehydrated.
  • Standing up very suddenly from a lying position.

Exams & Tests

Your provider will ask questions to determine whether you simply fainted, or if something else happened (such as a seizure or heart rhythm disturbance), and to figure out the cause of the episode. If someone saw the fainting episode, their description of the event may be helpful.

The physical exam will focus on your heart, lungs, and nervous system. Your blood pressure may be checked while you are in different positions, such as lying down and standing. People with a suspected arrhythmia may need to be admitted to a hospital for testing.

Tests that may be ordered include:

  • Blood tests for anemia or body chemical imbalances
  • Cardiac rhythm monitoring
  • Echocardiogram
  • Electrocardiogram (ECG)
  • Electroencephalogram (EEG)
  • Holter monitor
  • X-ray of the chest

Treatment Of Fainting

Treatment depends on the cause.