A stroke is a condition in which usually blood flow to the brain is interrupted. This leads to the death of some brain cells. Since brain cells do not regrow, there is always some permanent damage from a stroke, although the exact extent of that damage depends a lot on what other medical problems your father has and how large the stroke was in the first place.
It will be very important for your father to follow up closely with his internal medicine doctor
. In most cases, it is very important to control the risk for a second stroke by aggressively controlling blood pressure, diabetes, and other medical conditions and also by taking blood thinners like aspirin. His doctor will be able to help him determine exactly which medications he needs to take.
In addition, it is usually important to engage in a physical therapy regimen, as this will help your father regain strength and coordination in which ever parts of his body have been affected by the stroke. Typically, with patience and dedication, a stroke victim can recover a significant amount of the lost function.
Encourage your father to follow up with his doctors
on a regular basis!