TIA stands for Transient Ischemic Attack. In this type of stroke, which usually occurs in older people, the person has symptoms of a stroke (loss of muscle tone or paralysis on one side, slurred or confused speech, sudden blindness, confusion, and/or severe headache), but the symptoms only last a few hours. It is caused by a temporary blood clot in the person’s brain, which blocks blood flow. When the blood clot moves through the vessel, the symptoms stop. If you or someone you are with is experiencing a TIA, call 911 (or the emergency number in your area).