Alternative names 
Passed out; Lightheadedness - fainting; Syncope; Vasovagal


Fainting is a temporary loss of consciousness due to a drop in blood flow to the brain. The episode is brief (lasting less than a couple of minutes) and is followed by rapid and complete recovery. You may feel lightheaded or dizzy before fainting.

A longer, deeper state of unconsciousness is often called a coma.


When you faint, you not only experience loss of consciousness, but also loss of muscle tone and paleness in your face. You may also feel weak or nauseated just prior to fainting and have the sense that surrounding noises are fading into the background.

Common Causes

Fainting may occur while you are urinating, having a bowel movement (especially if straining), coughing strenuously, or when you have been standing in one place too long. Fainting can also be related to fear, severe pain, or emotional distress.

A sudden drop in blood pressure can cause you to faint. This may happen if you are bleeding or severely dehydrated. It can also happen if you stand up very suddenly from a lying down position.

Certain medications can lead to fainting because of a drop in your blood pressure or other reason. Common drugs that contribute to fainting include those for anxiety, high blood pressure, nasal congestion, and allergies.

Other reasons you may faint include hyperventilation, use of alcohol or drugs, or low blood sugar.

Less common but more serious reasons include heart disease (like abnormal heart rhythm or heart attack) and stroke.

Home Care
If you have a history of fainting and have been evaluated medically, follow your doctor’s instructions for how to prevent fainting episodes. For example, if you know the situations that cause you to faint, these should be avoided or changed. Avoid sudden changes in posture. Get up from a lying or seated position slowly and gradually. When having blood drawn (if this makes you faint), tell the technician and make sure that you are lying down.

Immediate treatment for fainting includes:

  • Check the person’s airway and breathing. If necessary, call 911 and begin rescue breathing and CPR.  
  • Loosen tight clothing around the neck.  
  • Keep the affected person lying down for at least 10 to 15 minutes, preferably in a cool and quiet space. If the person cannot lie down, have him sit forward and lower his head below the levels of the shoulders, between the knees.  
  • If the person has vomited, turn him or her to one side to prevent choking  
  • Elevate the feet above the level of the heart (about 12 inches).

Call your health care provider if

Call 911 if the person who fainted:

  • Fell from a height, especially if injured or bleeding.  
  • Does not regain consciousness quickly (within a couple of minutes).  
  • Is pregnant or over 50 years old.  
  • Has diabetes. (Check medical identification bracelets.)  
  • Feels chest pain, pressure, or discomfort; pounding or irregular heartbeat; or has loss of speech, visual disturbances, or inability to move one or more limbs.  
  • Has convulsions, tongue trauma, or loss of bowel control.

Even if it’s not an emergency situation, people should be evaluated by a doctor when they have never fainted before, if they are fainting frequently, or they have new symptoms associated with fainting. Call for an appointment to be seen as soon as possible.

What to expect at your health care provider’s office

When you see your doctor, the focus of the questions will be to determine whether you fainted or if somthing else happened (like a seizure) and to figure out the cause of the fainting episode.

The questions will include:

  • How would you describe the dizziness that you felt before fainting? Did you feel lightheaded, off balance, or like the room was spinning?  
  • Was the faint associated with convulsions (jerking muscle movements), tongue trauma, or loss of control of your bowels?  
  • When you regained consciousness were you aware of your surroundings or were you confused?  
  • Did you experience chest pain or heart palpitations when you fainted?  
  • Is this the first time you fainted?  
  • When did you faint? What were you doing before it occured? For example, were you going to the bathroom, coughing, or standing for a long time?  
  • Does fainting occur when you change positions - for example, go from lying to standing?

The physical examination will focus on your heart, lungs, and nervous system. Your blood pressure may be measured in several different positions.

Tests that may be performed include:

  • ECG  
  • Holter monitor  
  • X-ray of the chest  
  • Echocardiogram  
  • EEG

Johns Hopkins patient information

Last revised: December 8, 2012
by Brenda A. Kuper, M.D.

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All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.