A stroke occurs when blood flow to the brain stops. Within minutes of a stroke occurring, brain cells begin to die. There are three types of stroke:

• Ischemic stroke is caused by a blood clot that blocks or plugs a blood vessel in the brain.

• Hemorrhagic stroke is caused by a blood vessel that breaks and bleeds into the brain.

• Transient ischemic attacks (TIAs) or "mini strokes" occur when the blood supply to the brain is briefly interrupted.

Quality treatment for acute stroke must be timely and efficient to prevent brain tissue death, which may be fatal. However, patients may not seek medical treatment quickly enough to prevent tissue death. Better processes of care in hospitals may reduce the risk of death (mortality) from stroke if patients seek medical care in a timely manner.