A stroke occurs when a clot blocks blood supply to part of the brain (ischemic stroke) or a blood vessel in or around the brain ruptures (hemorrhagic stroke). As a result, parts of the brain become damaged or die.
The abilities lost or affected by a stroke depend on the extent of the brain damage and where in the brain the stroke occurred. Some brain cells may be only temporarily damaged and may resume functioning.
The brain is also capable of reorganizing its own functions or reassigning a different region of the brain to “take over” for the damaged area. Stroke survivors sometimes experience remarkable recoveries and can show signs of improvement for the rest of their lives.