Minor correction. Strokes are caused by blood clots or blockage in the brain.
A stroke is more accurately called a cerebral vascular accident (CVA). It may be caused by either an occlusion (embolus) or by hemorrhage (bleed) into the brain tissue. By far, the most common cause is an embolus. Both result in damage to brain tissue.
A CVA is typically determined by the duration of the symptoms. Thus, temporary symptoms of < 24 hours duration are classified as transient ischemic attack (TIA).
Appreciate your clarification.