Fainting

Fainting is a sudden, brief loss of consciousness. When people faint, or pass out, they usually fall down. After they are lying down, most people will recover quickly.

The term doctors use for fainting is syncope (say "SING-kuh-pee").

Fainting one time is usually nothing to worry about. But it is a good idea to see your doctor, because fainting could have a serious cause.

Fast or slow arrhythmias may cause you to pass out. You may fall and injure your head, break an arm or leg, or get other injuries. If you're driving, you may crash. Also, passing out (syncope) may be a sign that you're at risk for a life-threatening arrhythmia.

To find the cause of fainting, a doctor will do a physical exam and ask questions about the fainting episode.

The doctor may want to do tests. These tests may include:

• Blood tests.
• Heart tests such as ECG, ambulatory monitoring (with a Holter monitor or event monitor, for example), echocardiogram, or an exercise stress test.
• A tilt table test. This test checks how your body responds to changes in position.
• Tests for nervous system problems, such as CT scan of the head, MRI of the brain, or EEG.

If you know you tend to faint at certain times (such as when you get a shot or have blood drawn), it may help to:

• Sit with your head between your knees or lie down if you feel faint or have warning signs such as feeling dizzy, weak, warm, or sick to your stomach.
• Drink plenty of fluids so you don't get dehydrated.
• Stand up slowly.

You may need to see a doctor if you have ongoing dizziness or fainting. Ask your doctor when it is safe to drive.