Fainting occurs when the blood supply to your brain is momentarily inadequate, causing you to lose consciousness. This loss of consciousness is usually brief.
Fainting can have no medical significance, or the cause can be a serious disorder. Therefore, treat loss of consciousness as a medical emergency until the signs and symptoms are relieved and the cause is known. Discuss recurrent fainting spells with your doctor.
If you feel faint
Lie down or sit down. To reduce the chance of fainting again, don't get up too quickly.
Place your head between your knees if you sit down.
If someone else faints
Position the person on his or her back. If the person is breathing, restore blood flow to the brain by raising the person's legs above heart level — about 12 inches (30 centimeters) — if possible. Loosen belts, collars or other constrictive clothing. To reduce the chance of fainting again, don't get the person up too quickly. If the person doesn't regain consciousness within one minute, call 911 or your local emergency number.
Check the person's airway to be sure it's clear. Watch for vomiting.
Check for signs of circulation (breathing, coughing or movement). If absent, begin CPR. Call 911 or your local emergency number. Continue CPR until help arrives or the person responds and begins to breathe.