Get the facts about nutrition and dietary information. Learn about healthy food, vitamins and dietary supplements.

Symptoms, diagnosis and prevention, rehabilitaion & information of specific conditions.

Not Feeling well?


secure email

Keep Your Personal Information Safe

Health Encylopedia

Definition Fainting is a temporary loss of consciousness as a result of transiently decreased blood flow to the brain. Light-headedness is a vague feeling of dizziness or a feeling like a person is going to faint.
Alternative Names Passed out; Light-headedness - fainting; Syncopal episode; Syncope
Considerations Fainting (syncope) can be caused by any condition causing a reduction of circulating blood flow to the brain. The cause of fainting should be evaluated by a health care provider. Fainting or syncope is characterized by sudden pallor , loss of consciousness , and occasionally slight twitching or convulsive movements. For a parent, seeing their child faint may be a terrifying experience. A simple faint (vasovagal faint) is rarely preceded by pain, pressure, constriction in the chest, or shortness of breath . It can be preceded by weakness , giddiness, nausea , dizziness , and a sense that the surrounding noise is growing fainter and fainter. Pathologic fainting or syncope may also be associated with heart conditions, most often abnormal heart rhythms ( arrhythmias ).
Common Causes Light-headedness can accompany mild illness such as the flu or the common cold , and may be a symptom of anxiety . Light-headedness without other symptoms is usually not serious. Actual fainting can be caused by any condition restricting blood flow to the brain; this can be positional, physiological (an automatic body response to a stimulus ), or a result of drugs or activity. The more common causes include:
  • rigid standing at attention
  • arising quickly from a prone position
  • pressure on the neck (tight collar)
  • abnormal
  • heart rate or rhythm
  • low blood pressure
  • (
  • hypotension )
  • severe pain, injury or fright
  • alcohol or drugs including anxiolytics, antihistamines, antihypertensives, vasodilators, decongestants,
  • central nervous system depressants
  • strenuous
  • coughing , straining during a bowel movement or any other Valsalva maneuver (forced exhalation with closure of mouth and nose)
  • hyperventilation
  • Home Care
  • Follow your health care provider's recommendations.
  • Susceptible individuals should avoid situations known to cause fainting. Avoid sudden changes in posture. A person who becomes light-headed when they stand up should generate vigorous muscle activity before standing, and stand slowly. Immediate treatment for fainting includes:
  • Keep the affected person lying flat or sitting forward with the head bent below the knees.
  • Cool the room down or move the person to a cooler location if heat is a problem (This can be especially helpful for someone with a history of heart problems as a cause of fainting).
  • Call your health care provider if
  • there has been a complete
  • loss of consciousness , especially if it occurs after a head injury or if there is no readily identifiable cause (such as a susceptible individual who faints when they have blood drawn).
  • fainting is accompanied by a feeling that the room is spinning (
  • vertigo ) or any other symptoms.
  • fainting occurs in a susceptible person more often than rarely.
  • this is the first time a person has ever fainted.
  • medication or alcohol is suspected as the cause.
  • lightheadedness lasts for longer than 3 weeks.
  • What to expect at your health care provider's office The medical history will be obtained and a physical examination performed. Medical history questions may include:
  • quality
  • Does fainting occur with upright posture?
  • Does fainting occur with a change in body position?
  • time pattern
  • When did the fainting occur?
  • Is this the first time the person has fainted?
  • Was this a single incident or did it occur more than once?
  • How long did the episode last?
  • aggravating factors
  • Was there an apparent cause for the fainting?
  • If so, what was it?
  • Did it occur after
  • exercise ?
  • Did it occur after
  • coughing ?
  • other
  • Did the person actually lose consciousness or black out?
  • Were any other symptoms present before or after the person fainted?
  • There will be a detailed examination of the heart, lungs, and nervous system. The blood pressure may be measured in various positions. Diagnostic tests that may be performed include:
  • ECG
  • Holter monitor
  • X-ray of the chest
  • echocardiogram
  • If the fainting is determined to be a simple faint, no treatment is usually recommended except as noted in the home care section. Fainting in children often becomes less common as the person grows older.
  • After seeing your health care provider: You may want to add a diagnosis related to fainting to your personal medical record.

    BMI Calculator

    Weight Height
    Body Mass Index
    Your Category is 

    Healthcare News