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What Is Syncope?

Syncope means fainting.

What Causes Syncope?

People faint most often because of a sudden drop in blood pressure from standing up too fast.

The usual cause is related to not enough blood flow to the brain, so not enough oxygen gets to the brain. Blood collecting in veins in the lower body because of gravity (venous pooling) or straining (Valsalva’s maneuver) may prevent blood from reaching the brain. Damaged or stiff blood vessels and abnormal heart rhythms (arrhythmias) may also reduce blood flow.

Low blood pressure, ineffective pumping by the heart because of heart disease (heart failure), or heart valve abnormalities may cause fainting, as can anemia (low red blood cell count), drugs (especially those for high blood pressure), lung diseases, and too much water loss from the body (dehydration).

One type of fainting called vasovagal syncope refers to overstimulation of the vagus nerve, which lowers blood pressure and causes fainting. This type may occur with anxiety, pain, urination, or coughing.

What Are the Symptoms of Syncope?

Symptoms are sudden brief loss of consciousness, and heart rate may be too fast or irregular (palpitations) or too slow.

How Is Syncope Diagnosed?

The health care provider will diagnose syncope on the basis of a history of fainting or feeling faint.

The health care provider will obtain a medical history, do a physical examination and electrocardiography (ECG), and take blood pressure with the person in different positions (lying, sitting, standing, after exercise). Tilt table testing is a test done by specialists when the cause of syncope is unclear. It can check for symptoms with the body in different positions.

Blood sugar (glucose) level and blood count (hematocrit) may be checked.

If an irregular heartbeat is suspected, the health care provider may use a Holter monitor, a device worn at home and work to monitor the heart rhythm.

How Is Syncope Treated?

If not enough blood is pumped by the heart, the heart’s condition must be checked. The health care provider may suggest seeing a heart specialist (cardiologist) for additional tests.

For people with low blood pressure (hypotension) or heart disease, drugs that may be causing fainting are stopped on a trial basis.

DOs and DON’Ts in Managing Syncope:

  • DO keep a record of fainting, for example, it happens when you suddenly stand from being seated.
  • DO eat a proper diet and drink enough fluids. These are needed for avoiding fainting caused by low blood sugar and dehydration.
  • DO sit or lie down if you feel faint, to help improve blood flow to the brain. Drink plenty of fluids once you are able to drink. If you are a diabetic and have low blood sugar, eat something.
  • DO call your health care provider if you have fainting with chest pain, shortness of breath, or history of heart disease.
  • DON’T ignore any fainting episodes. Call your health care provider.
  • DON’T put yourself in situations such as driving that make your fainting worse.

Contact the following source:

  • American Heart Association
    Tel: (800) 242-8721

Copyright © 2016 by Saunders, an imprint of Elsevier, Inc.

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