When you have an ischemic stroke, the oxygen-rich blood supply to part of your brain is reduced. With a hemorrhagic stroke, there is bleeding in the brain.

• After about 4 minutes without blood and oxygen, brain cells become damaged and may die.
• The body tries to restore blood and oxygen to the cells by enlarging other blood vessels (arteries) near the area.
• If blood supply is not restored, permanent brain damage usually occurs.

When brain cells are damaged or die, the body parts controlled by those cells cannot function. The loss of function may be mild or severe and temporary or permanent. This depends on where and how much of the brain is damaged and how fast the blood supply can be returned to the affected cells.

If you have symptoms of a stroke, seek emergency medical care . Life-threatening complications may occur after a stroke. Early treatment may decrease the amount of permanent damage to brain cells, decreasing the amount of disability.

Stroke is the most common nervous system–related cause of physical disability. Of people who survive a stroke, half will still have some disability 6 months after the stroke.

Recovery depends on the location and amount of brain damage caused by the stroke, the ability of other healthy areas of the brain to take over functioning for the damaged areas, and rehabilitation. In general, the less damage there is to the brain tissue, the less disability results and the greater the chances of a successful recovery.

You have the greatest chance of regaining your abilities during the first few months after a stroke. Regaining some abilities, such as speech, comes slowly, if at all. About half of all people who have a stroke will have some long-term problems with talking, understanding, and decision-making. They also may have changes in behavior that affect their relationships with family and friends.

Long-term complications of a stroke, such as depression and pneumonia, may develop right away or months to years after a stroke. Some long-term complications may be prevented with proper home treatment and medical follow-up. For more information, see the Home Treatment section of this topic.

What to expect after a stroke

In addition to the more obvious physical problems you have after a stroke, you (or a caregiver) may also notice:

• Changes in speed of action.
• Changes in judgment.
• Changes in emotions.
• Changes in perception (the ability to judge distance, size, position, rate of movement, form, and how parts relate to the whole).
• Memory problems.
• Problems from neglecting the affected side of the body.

If you have concerns, discuss them with your doctor. Your doctor will provide support and may offer other suggestions for dealing with these issues.