Stroke is a sudden and severe event in which blood is blocked and prevented from getting to a part of the brain, resulting in damage to that brain area. When the symptoms from a stroke last for 24 hours or less, followed by full recovery of lost functions, the episode is called a transient ischemic attack (TIA).

Symptoms
Symptoms of stroke can develop immediately or over several days. They include loss and/or impairment of movement, sensation, and specific functions controlled by the part of the brain that is damaged, such as loss or slurring of speech if it is the speech center of the brain that is damaged. Other symptoms include headaches, dizziness, confusion, difficulty swallowing, and visual problems. About one third of all cases of stroke are fatal, another third results in partial loss of function, and one third of stroke victims completely recover. Many people who become paralyzed by a stroke are able learn to walk again. However, loss of intellectual functioning tends to not recover as well. TIAs usually last only several minutes and are warning signals.

Causes
Stroke is the most common cause of neurological damage in the industrialized world. The most common causes of stroke are arteriosclerosis (thickening of lining of arteries), high blood pressure (hypertension), or both. Other risk factors include old age, smoking, a recent heart attack, elevated blood fats, diabetes, blood platelet stickiness associated with raised levels of red cells, deficiencies of nutrients that prevent stickiness such as vitamin B6, irregular heart beat (atrial fibrillation), oral contraceptives in women under 50 years of age, and history of a damaged heart valve. To protect yourself against stroke, screen for and address each of these conditions before it is too late.

Important: Stroke patients who receive hyperbaric oxygen therapy within the first six hours of a stroke often significantly improve soon afterwards. In addition, even stroke that has occurred years in the past can respond if properly treated. The cells that are damaged by stroke are in some cases not dead, simply dormant.

Caution: Stroke requires immediate medical attention. If you or your loved one suffers a stroke, get to a hospital immediately.

Treatment