Fainting is a brief loss of consciousness due to a drop in blood
flow to the brain. The episode lasts less than a couple of
minutes and you recover from it quickly and completely. You may
feel light-headed or dizzy before fainting. When you faint, you
not only lose consciousness, but you also lose muscle tone and
the color in your face (pallor). You may also feel weak or
nauseated just before fainting. You may have the sense that
noises are fading into the background. Fainting may occur while
you: Cough very hard Have a bowel movement (especially if you
are straining) Have been standing in one place for too long
Fainting can also be related to: Other causes of fainting:
Certain medications, including those used for anxiety,
depression, high blood pressure, and allergies (these drugs may
cause a drop in blood pressure) Sudden drop in blood pressure
(such as from bleeding or being severely dehydrated) Standing up
very suddenly from a lying position Less common but more serious
reasons for fainting include heart