Skip navigation | ||
|
||
Medical Encyclopedia |
|
Other encyclopedia topics: | A-Ag Ah-Ap Aq-Az B-Bk Bl-Bz C-Cg Ch-Co Cp-Cz D-Di Dj-Dz E-Ep Eq-Ez F G H-Hf Hg-Hz I-In Io-Iz J K L-Ln Lo-Lz M-Mf Mg-Mz N O P-Pl Pm-Pz Q R S-Sh Si-Sp Sq-Sz T-Tn To-Tz U V W X Y Z 0-9 |
Contents of this page: | |
Alternative names
Passed out; Lightheadedness - fainting; Syncope; VasovagalDefinition Return to top
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.
Considerations Return to top
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 Return to top
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 Return to top
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.Call your health care provider if Return to top
Call 911 if the person who fainted:
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 Return to top
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:
Home | Health Topics | Drug Information | Encyclopedia | Dictionary | News | Directories | Other Resources | |
Copyright | Privacy | Accessibility | Selection Guidelines U.S. National Library of Medicine, 8600 Rockville Pike, Bethesda, MD 20894 National Institutes of Health | Department of Health & Human Services |
Page last updated: 28 October 2004 |