Syncope, or fainting, is a sudden loss of consciousness caused by decreased blood flow to the brain. Recovery occurs within seconds or minutes for many causes of fainting. Approximately 3 to 4 percent of people, mostly the elderly, experience episodes of fainting.

You may experience the following signs and symptoms before you faint:

• Lightheadedness 
• Blurred vision 
• Sweating 
• Heaviness in your lower limbs 
• Giddiness 
• Confusion 
• Yawning 
• Nausea, and sometimes vomiting 

During a fainting episode, in addition to loss of consciousness, you may experience the following symptoms:

• Abnormal paleness 
• Falling down if standing, slumping if seated 
• Spasmodic jerks of your body 
• Weak pulse 
• Drop in blood pressure 

Fainting often occurs from a simple, non-medical cause, but may be the result of a serious health condition, such as heart disease (decreased blood flow to the heart and/or irregular heart rhythm), low blood sugar (often related to diabetes), seizures, panic attacks, and problems regulating blood pressure.

People with the following conditions or characteristics are at risk for fainting:

• Over 65 years of age
• Preexisting heart disease
• Recreational drug use
• Taking certain medications such as antihypertensives, insulin, oral hypoglycemics, diuretics, antiarrhythmics, or anticoagulants
• Pregnancy

If you have fainted, you should see your healthcare provider. He or she will ask questions, do a physical examination, and perform diagnostic tests, which may include blood tests, electrocardiogram (ECG), and imaging of the brain, such as magnetic resonance imaging (MRI). Your provider will focus on symptoms associated with the current fainting episode, medications you take, preexisting medical conditions, and your description of any similar episodes you may have experienced in the past. This will help your provider pinpoint the cause of the fainting episodes and identify or rule out particular health conditions. If seizures are suspected, he or she may perform a test called an electroencephalogram (EEG).

Some cases of fainting may be preventable, depending on the cause.

• Avoid fatigue, hunger, and stress. 
• Avoid changing positions quickly, especially rising from a sitting or lying-down position, for fainting caused by a change in blood pressure due to a sudden change in position. Sleep with the head of your bed elevated; wear elastic stockings to prevent pooling of blood in your lower legs; avoid standing for long periods; avoid diuretics and other medicines that can contribute to the problem (your healthcare provider can help you identify these agents). 
• Avoid tight clothing around the neck for fainting caused by a rise in blood pressure. Turn the whole body and not just the head when looking around. 
• Avoid standing still for long periods for fainting that happens often. To prevent injuries, cover floors with thick carpeting and avoid driving or operating mechanical equipment. 
• Avoid caffeine and alcohol.

Any serious underlying health condition must be treated. At the time of the fainting episode, place the person in a position that increases blood flow to the brain (such as elevating the legs so that blood flows with gravity back toward the head). A pregnant woman should lie on her left side to relieve pressure on the aorta, the largest blood vessel in the body. Loosen all tight clothing, apply cold water to the person's face, and turn the person's head to the side to prevent vomiting or choking.

When irregular heart rhythm causes fainting, your healthcare provider may prescribe medications such as beta-blockers, after some tests. Mineralocorticoids (such as fludrocortisone), a substance involved in regulating the balance of salt and water in the body, or salt tablets may be prescribed in the case of decreased circulation of blood or pooling of blood in the veins.

In some cases where fainting is caused by an underlying heart condition, such as slow or rapid heartbeat, a cardiac pacemaker may be necessary.

You may experience warning signs before fainting. Autogenic training (a hypnosis-based healing method that consists of a series of mental exercises designed to relax the individual and to relieve suppressed anger, emotion, and tension), deep breathing, relaxation techniques, and biofeedback may help you become aware of pre-fainting symptoms to avoid fainting. These techniques may also help you control fainting related to nervous system regulation of your blood pressure. Nutrition, herbs, and acupuncture may help treat fainting; see following sections for more details.

As stated earlier, low blood sugar sometimes plays a role in fainting, particularly in combination with low blood pressure. Therefore, if you are prone to fainting for this reason, make sure you eat the appropriate amount and type of calories. This is especially important if you are elderly or have a history of fainting. If your body has trouble processing sugar (as in the case of diabetes), you may need to avoid refined foods and sugar, and eat small, frequent meals high in protein. It is best to consult a registered dietitian to determine the right nutritional program for your specific needs.

In a case report about one 38-year-old man, licorice root (Glycyrrhiza glabra) combined with a high-salt diet helped clear up fainting due to low blood pressure and nervous system problems. However, you should not use licorice root if you have high blood pressure, low levels of potassium, severe kidney disease, or if you are pregnant. Even if you have normal blood pressure, a healthcare provider should monitor you if you take licorice.

Some herbs, used alone and together, may help protect your heart. For instance, hawthorn (Crataegus monogyna) may help maintain blood pressure, control blood flow through the heart, and treat irregular heartbeat. Many herbs, however, can have toxic effects on your heart if not used correctly, and may cause fainting or more serious problems. Use herbal therapies only under the supervision of an experienced healthcare provider.

No scientific literature supports the use of homeopathy for fainting specifically. But an experienced and certified homeopath may assess your individual constitution and symptoms, and then recommend one of the following remedies for fainting or pre-fainting symptoms:

• Carbo vegetabilis for fainting or lightheadedness after rising in the morning, from loss of fluids, or from becoming overheated
• Opium for fainting due to excitement or fright
• Sepia for fainting following prolonged standing, exercise, or fluid loss due to fever

Acupuncture may be helpful in treating syncope. A clinical analysis of 102 serious cases of loss of consciousness, including 87 semi-comatose and 15 comatose patients, reviewed the use of acupuncture and moxibustion (burning herbs over the skin) to revive people who could not be revived with traditional Chinese or Western drugs. Seventy-eight patients had either excellent or good results (they were conscious, pulse was normal or nearly normal and stable, and drug treatment was at least partially halted during the procedure). Three patients had fair results (they were conscious, blood pressure was nearly normal but not stable, and pulse was scattered and weak). The treatment failed in the remaining 21 patients, who were unable to be resuscitated from coma and died after all treatments—including Western and acupuncture/moxibustion—failed.

Acupuncture is known for rarely causing side effects or complications. But some patients faint during acupuncture treatments. Called "needle fainting" in Chinese medicine, this comes from lowered blood pressure. It is not considered a serious complication of acupuncture. Needle fainting may be easily remedied or prevented by changing the positions of the patient and the needles.

In most people, simple fainting is not a sign of a life-threatening disease, particularly if it only happens once. The elderly are at increased risk for injury after a fainting episode, especially from fractures.

Many people with syncope, especially the elderly and those with preexisting heart disease, may be hospitalized to look for a cause. Continuous ECG monitoring can identify irregular heartbeat as a cause of fainting, especially in people who have recurring fainting episodes.

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