A transient ischemic attack (TIA) is a temporary blockage of blood flow to the brain, which results in a lack of oxygen to the brain cells. TIAs are often referred to as "mini-strokes" because they have similar symptoms to a stroke, but they usually last only a few minutes and do not cause permanent damage. The symptoms of a TIA include sudden onset of weakness, numbness, or paralysis on one side of the body, slurred speech or difficulty understanding others, blindness in one or both eyes, dizziness, and loss of balance or coordination. TIAs are caused by a temporary disruption in the blood supply to part of the brain, usually due to a blood clot that has formed elsewhere in the body and traveled to the brain. The underlying cause of a TIA is often a buildup of cholesterol-containing fatty deposits called plaques in an artery or one of its branches that supplies oxygen and nutrients to the brain. TIAs are a warning sign that a person is at risk for a more serious and debilitating stroke, and about one-third of those who have a TIA will have an acute stroke sometime in the future. The most important treatable factors linked to TIAs and stroke are high blood pressure, cigarette smoking, heart disease, carotid artery disease, diabetes, and heavy use of alcohol. If you think you may be having a TIA, it is important to seek immediate medical help by calling 911 or the local emergency number.