Syncope (Fainting)

The National Institute of Neurological Disorders and Stroke (NINDS) says syncope is the temporary loss of consciousness due to a sudden decline in blood flow to the brain. (Read about "The Brain") This is often referred to as fainting or passing out. It's usually related to temporary insufficient blood flow to the brain.

The American Heart Association calls syncope a common problem, saying it accounts for 3 percent of emergency room visits and 6 percent of hospital admissions. NINDS says it can be caused by an irregular cardiac rate or rhythm (Read about "Arrhythmia") or by changes of blood volume or distribution.

Syncope can occur in otherwise healthy people. Syncope can even occur after prolonged coughing or during urination (micturition syncope). The patient feels faint, dizzy, or lightheaded (presyncope), or loses consciousness (syncope).

AHA says the most common cause of fainting is a benign one called neurally mediated syncope (NMS). It is more common in children and young adults. It happens when blood pressure drops and less blood reaches the brain. It can happen on sudden standing or while standing for a period of time. Nausea, lightheadedness and fuzzy vision often occur just before a fainting spell. Placing the person in a reclining position will help restore the blood flow, according to AHA.

Other conditions that can cause fainting include:

• panic disorder (Read about "Panic Disorder")
• low blood sugar from diabetes (Read about "Diabetes")
• medication (Read about "Medicine Safety")
• seizures (Read about "Seizures")

AHA does say that syncope can indicate a serious problem particularly when it occurs with exercise, heart palpitations or other heart irregularities (Read about "The Heart & Cardiovascular System") or if there is a family history (Read about "Family Health History") of sudden death from cardiac arrest. (Read about "Cardiac Arrest") In these cases, you should consult your doctor or healthcare provider immediately.

If your doctor suspects that there is a serious cardiac cause for the syncope, tests may be needed. Your blood pressure and heart rate may be measured while you're lying down and while you're standing. An electrocardiogram may be used to test for abnormal heart rhythms. (Read about "EKG - Electrocardiogram") You may also be connected to a portable device called a Holter monitor, which is a recorder that monitors your heart rhythm continuously for 24 hours or more. A tilt test may be used also. During the test, heart rate, blood pressure or other measurements can be made while you lie on a table which is tilted so you can be monitored in different positions from lying down to standing upright.

Related Information:

    Arrhythmia

    Cardiovascular Tests