A stroke is always a medical emergency. A stroke is not a heart attack. A stroke happens when the supply of blood to the brain is suddenly interrupted. Some strokes are fatal while others cause permanent or temporary disability. The longer a stroke remains untreated, the greater the chance of stroke related brain damage. Emergency medical treatment soon after symptoms begin improves the chance of survival and successful rehabilitation. Facial weakness, arm weakness and difficulty with speech are the most common symptoms or signs of stroke, but they are not the only signs. Weakness or numbness or paralysis of the face, arm or leg on either or both sides of the body. Difficulty speaking or understanding Dizziness, loss of balance or an unexplained fall Loss of vision, sudden blurring or decreased vision in one or both eyes Headache, usually severe and abrupt onset or unexplained change in the pattern of headaches. Difficulty swallowing.