Light-headedness makes a person feel that he or she is about to faint or pass out. It is caused by a momentary drop in blood pressure and blood flow to the head.

Nausea or vomiting sometimes accompanies light-headedness. Symptoms usually improve or go away after lying down.

It is common to feel light-headed occasionally. Light-headedness often occurs when a person gets up too quickly from a seated or lying position (orthostatic hypotension).

Unlike vertigo, light-headedness does not produce a sensation of movement. Vertigo causes a spinning or whirling sensation that may lead to nausea or vomiting, loss of balance, trouble walking or standing, and falling.