Loss of consciousness, also known as fainting or syncope, is a temporary loss of consciousness caused by a decrease in blood flow to the brain. It is usually caused by a sudden drop in blood pressure, which can be triggered by a variety of factors such as standing up too quickly, dehydration, or emotional stress. Symptoms of fainting include dizziness, lightheadedness, and confusion. Treatment for fainting typically involves restoring blood flow to the brain, and may include lying down, drinking fluids, or taking medications.