Our Fainting (Syncope) Main Article provides a comprehensive look at the who, what, when and how of Fainting (Syncope)
Medical Definition of Fainting (syncope)
Fainting (syncope): Partial or complete loss of consciousness with interruption of awareness of oneself and ones surroundings. When the loss of consciousness is temporary and there is spontaneous recovery, it is referred to as syncope or, in nonmedical quarters, fainting. Syncope accounts for one in every 30 visits to an emergency room. It is pronounced sin-ko-pea.
Syncope is due to a temporary reduction in blood flow and therefore a shortage of oxygen to the brain. This leads to lightheadedness or a "black out" episode, a loss of consciousness. Temporary impairment of the blood supply to the brain can be caused by heart conditions and by conditions that do not directly involve the heart:
Non-cardiac causes: Syncope is most commonly caused by conditions that do not directly involve the heart. These conditions include:
Cardiac causes: Heart conditions that can cause syncope or fainting due to temporary loss of consciousness include:
To be sure, many of the causes of temporary loss of consciousness can be detected by a careful history. Dizziness after standing up in an older person suggests postural hypotension. Temporary loss of consciousness after urinating, defecating, or coughing suggests situational syncope. Cardiac causes of temporary loss of consciousness such as aortic stenosis or cardiomyopathy are suggested by the occurrence of the event during exercise. Signs of weakness localized to certain areas of the body with temporary loss of consciousness suggest stroke.
The blood pressure and pulse are tested in the lying, sitting, and standing positions. Unequal blood pressures in each arm is a sign of aortic dissection. The heart is examined with a stethoscope to listen for sounds that can indicate valve abnormalities. The nervous system is tested for sensation, reflexes, and motor function to detect conditions of the nerves and brain. An EKG is done to check for abnormal heart rhythms. Other tests may include echocardiograms, rhythm monitoring tests (heart event recorders), and electrophysiologic testing for abnormalities of the heart's electrical system.
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