From CardioWiki

Syncope is a symptom that is manifested by a sudden, short-term loss of consciousness and accompanied by a fall in muscle tone. It occurs as a result of transient hypoperfusion of the brain. In patients with syncope, pale skin, hyperhidrosis, lack of spontaneous activity, hypotension, cold extremities, weak pulse, frequent shallow breathing are observed. The duration of the syncope is usually about 20 seconds.

After fainting, the patient's condition is usually restored quickly and completely, but weakness and fatigue are noted. Older patients may experience retrograde amnesia. Syncope are recorded in 30% of people at least once.

It is important to diagnose the causes that caused syncope, because they can be life-threatening conditions (tachyarrhythmias, heart block).