Stroke is a leading cause of death and disability in adults. According to studies, the prevalence of stroke in India is about 203 cases per 100,000 population above 20 years which amounts to about a total of 1 million cases. The most worldwide cause of stroke is high blood pressure. This makes high blood pressure or hypertension the single most important risk factor.What is Stroke?A stroke can be defined as a sudden loss of brain function due to interruption of the blood supply to the brain. It is caused by an acute vascular event such as interruption of blood supply (ischemic strokes) and/or bleeding into the brain tissue (hemorrhagic strokes). Interruption of the blood supply results in a deficiency of oxygen and other nutrients to the brain tissue. As the brain tissues use oxygen at an exceptionally high rate, interruption of the oxygen and other nutrients to the brain even for a few seconds can cause extensive damage and serious complications.Blood Supply to the BrainBlood supply to the brain can be interrupted because of:A block by a clot or other debris in the blood vessel, which supplies blood to the brain. If this happens, you are having an ischemic stroke. This type of stroke is more common (85 % of all strokes are of ischemic stroke)A hemorrhagic stroke occurs when there is a rupture of the blood vessels in the brain, which then leads to bleeding in the brain tissue and interruption of blood supply to tissues located after the point of ruptureBoth these are potentially serious and can cause extensive damage and potentially serious complications.The Influence of High Blood PressureThe risk stroke due to high blood pressure is directly related to the level of blood pressure that is higher the blood pressure higher is the risk of stroke. The risk of stroke is lesser in patients with well-controlled blood pressure as compared to patients with poorly controlled blood pressure.Warning Signs of StrokeThe signs and symptoms of stroke depend on the area of the brain which is affected. But the symptoms that are a cause for concern include:Loss of consciousnessNumbness or Weakness of any part of the bodyLoss of sensation in any part of the bodyDeviation of mouth to one sideDifficulty in speakingDifficulty in understanding conversationSudden visual defect in one or both eyesDizziness, giddiness, or confusionLoss of balance or unexplained fallsStroke is a serious and potentially life-threatening condition so never ignore your symptoms. In many people, the symptoms may last only for a few seconds. Consult your doctor or visit an emergency room immediately if you have symptoms of stroke even if they last only for a few seconds.