A stroke happens when the blood supply to part of the brain is interrupted. As a result brain cells are deprived of the oxygen and nutrients which they need. Some brain cells become damaged and others die.This disturbance could be due to blockage in the blood flow or rupture of blood vessels; depending on which parts of the brain the interruption occurs will affects the symptoms of the stroke, this could lead to loss of ability to speak, or use one side of the body (e.g. arm, face or leg) which can become paralyzed or there may be memory problems.
Sometimes this disturbance is temporary and for a short period time (within 24 hours), and the blood supply resume to that area by itself. This is called Transient Ischemic Aattack (TIA) or ‘mini-stroke’. If this disturbance persists for longer period, this is called a Stroke.
Ischaemic strokes are caused by blockages (usually blood clots) in one of the arteries supplying the brain. Clots can form in these arteries themselves or form in a blood vessel elsewhere in the body (e.g. heart or leg) and travel to the brain.
Haemorrhagic strokes are caused when one of the blood vessels supplying the brain bursts and causing a bleed. The most common cause is high blood pressure which damages and weakens the arteries making them more likely to tear.
The exact symptoms of stroke vary person to person as they depend on which parts of the brain are affected.However, the most common symptom are physical affecting usually one side of body (causing numbness, weakness), drooping on one side of the face, speech problems (slurred speech, muddled words) or visual problems (blurred vision, loss of vision). Severity of the symptoms usually depends on how much damage has been done to the brain.