What is TIA?

A transient ischemic attack (TIA) occurs when blood flow to part of the brain is interrupted by a temporary blockage in an artery supplying the brain. The pathological mechanism of a TIA is identical to that of certain kinds of stroke, except that normal circulation is restored within 24 hours and no permanent brain damage occurs.

Most TIAs resolve within a few minutes to an hour. Symptoms appear suddenly and vary considerably depending on the part of the brain affected. Although TIA symptoms disappear completely without treatment, they often recur. Prompt medical attention is important: TIAs are a warning sign of an impending stroke.

What Causes Transient Ischemic Attack?

  • The majority of TIAs are associated with atherosclerosis, a buildup of plaques in the walls of the arteries. A TIA may develop when a plaque becomes substantial enough to reduce blood supply locally in an artery supplying the brain. More commonly, however, a TIA occurs when a small fragment of a plaque that has broken off from a blood vessel, or a blood clot (embolus), usually from the heart, travels to an artery supplying the brain and lodges in a site already narrowed by atherosclerosis.
  • Major risk factors for TIAs include high blood pressure, heart disease, diabetes, smoking and aging.


Johns Hopkins Symptoms and Remedies: The Complete Home Medical Reference

Simeon Margolis, M.D., Ph.D., Medical Editor

Prepared by the Editors of The Johns Hopkins Medical Letter: Health After 50

Updated by Remedy Health Media

Publication Review By: the Editorial Staff at HealthCommunities.com

Published: 29 Aug 2011

Last Modified: 05 Mar 2015