By Mayo Clinic Staff
A stroke occurs when there's bleeding into your brain or when blood flow to your brain is blocked. Within minutes of being deprived of essential nutrients, brain cells start dying.
Seek immediate medical assistance. A stroke is a true emergency. The sooner treatment is given, the more likely it is that damage can be minimized. Every moment counts.
In the event of a possible stroke, use F.A.S.T. to help remember warning signs.
  • Face. Does the face droop on one side when the person tries to smile?
  • Arms. Is one arm lower when the person tries to raise both arms?
  • Speech. Can the person repeat a simple sentence? Is speech slurred or hard to understand?
  • Time. During a stroke every minute counts. If you observe any of these signs, call 911 or your local emergency number immediately.
Other signs and symptoms of a stroke, which come on suddenly, include:
  • Weakness or numbness on one side of the body, including either leg
  • Dimness, blurring or loss of vision, particularly in one eye
  • Severe headache — a bolt out of the blue — with no apparent cause
  • Unexplained dizziness, unsteadiness or a sudden fall, especially if accompanied by any of the other signs or symptoms
Risk factors for stroke include having high blood pressure, having had a previous stroke, smoking, having diabetes and having heart disease. Your risk of stroke increases as you age.