What are the differences between a tia and a stroke?

Duration: The main difference is in how long the neurological symptoms last. In a TIA they resolve fairly quickly (<1 day and often in an hour or two). In a stroke they last longer and are often permanent. The fact that the symptoms resolve with a TIA does not mean everything's okay--a TIA can be a serious sign of underlying vascular disease and should be thoroughly evaluated.

Time of symptoms: Tia symptoms should resolve within 24 hours. If not, then it would be considered a stroke.