FAINTING

General Information

DEFINITION--Sudden, temporary loss of consciousness due to insufficient oxygen reaching the brain.

BODY PARTS INVOLVED--Circulatory system (heart and blood vessels); brain.

SEX OR AGE MOST AFFECTED--Both sexes; all ages.

SIGNS & SYMPTOMS

• Sudden lightheadedness.
• General weakness, then falling.
• Blurred vision (sometimes).
• Nausea (sometimes).
• Paleness and sweating.
• Rapid heartbeat and rapid breathing. If heartbeat or breathing is not present, this may be cardiac arrest rather than fainting.

CAUSES--

A sudden decrease in blood flow to the brain. This may result from:

• Heartbeat abnormalities--too fast, too slow or irregular.
• Prolonged straining, such as from severe coughing or attempted bowel movements when constipated.
• Sudden emotional stress.
• Heart diseases that limit the amount of blood the heart pumps.
• Getting out of bed or a chair suddenly (orthostatic hypotension).
• Acute pain.
• Epilepsy.
• Heart attack (rare).

RISK INCREASES WITH

• Stress.
• Heart disease.
• Some drugs such as alcohol.
• Use of certain drugs, such as heart medications that slow the heartbeat. These include digitalis, beta-adrenergic blockers and other antihypertensive drugs.
• Hot, humid weather.
• Elderly.
• Diabetes mellitus.

HOW TO PREVENT

• Avoid sudden changes in physical activity.
• If fainting episodes are caused by medication, consult your doctor about changing drugs.

What To Expect

DIAGNOSTIC MEASURES--

• Observation of symptoms by those nearby.
• Medical history and exam by a doctor.
• Diagnostic tests for an underlying cause may include CT scan or MRI of the head and an EEG (See Glossary for all).

APPROPRIATE HEALTH CARE

• Care from bystanders.
• Self-care after regaining consciousness.
• Doctor's treatment, if fainting is caused by other conditions (see Causes).

POSSIBLE COMPLICATIONS

• Injury while fainting.
• Mistaking cardiac arrest for fainting.

PROBABLE OUTCOME--Simple fainting disappears in 1 or 2 minutes.

How To Treat

GENERAL MEASURES--

• If someone faints, check for breathing and a neck pulse. If neither is present: Dial 911 (emergency) for an ambulance or medical help. (If the victim is a child, perform 1 minute of lifesaving procedures first, then call 911). Then give first aid immediately. Begin cardiac massage and mouth-to-mouth breathing (CPR). Don't stop until help arrives.
• If someone faints, is breathing and has a pulse, leave the person on the ground and elevate both legs. This helps return blood to the heart. Person should remain lying down for 10-15 minutes.
• If you feel faint, sit down immediately and bend over, or lie down.
• If you are subject to frequent fainting spells, avoid activities in which fainting may endanger your life, such as climbing to high places, driving vehicles or operating dangerous machinery.

MEDICATION--Medication usually is not necessary for fainting. Medication may be necessary for underlying disorders.

ACTIVITY--Resume your normal activities as soon as you regain consciousness.

DIET--No special diet unless fainting episodes are caused by low blood sugar. If so, eat 5 or 6 small meals a day. The meals should be high in protein, high in complex carbohydrates and low in simple carbohydrates (sugar). Drink adequate fluids and avoid alcohol.

Call Your Doctor If

• An unconscious person has no pulse and is not breathing. Give CPR first.
• Someone faints and does not regain consciousness quickly.
• Fainting is a symptom of another condition (see Causes).