When fainting some people usually feel weak and unsteady before passing out usually for only a few seconds. It can happen when sitting down, standing or when one gets up too quickly. Before losing consciousness, they may experience:yawning, sudden sweat, nausea, fast and deep breathing, confusion, blurred vision or 'spots' in front of the eyes and ringing in the ears. Followed by loss of strength and loss of consciousness. It is common to feel confused and weak for 20-30 minutes after fainting.
Attribution: Straight Talk Foundation