Causes
Stroke is caused when blood supply to the brain is disrupted.
a) Blocked artery- The most common cause of a stroke is when an artery inside the brain gets blocked by a blood clot . This phenomenon is also known as thrombosis. In a typical case, the clot is formed in a blood vessel that has been constricted due to a variety of reasons (risk factors) such as hypertension, smoking, high cholesterol and diabetes. The region of the brain supplied by the blocked artery gets deprived of oxygen and eventually gets damaged.
b) Embolism- In this condition, a blood clot or a portion of the atherosclerotic plaque formed in the heart may break free and find its way to the brain where it may plug or block an artery. This causes a depletion in oxygen -rich blood to the brain, leading to an ‘embolic’ stroke.Â
c) Cerebral hemorrhage or ‘bleeding inside the brain’ occurs when a blood vessel inside the brain ruptures resulting in bleeding into the surrounding brain tissue. This may cause a reduction in oxygen- rich blood supply to the brain, leading to a stroke.
d) Subarachnoid hemorrhage-In this condition there is accumulation of blood beneath the arachnoid membrane that lines the brain. This may lead to stiff neck and headache and may lead to stroke and even death if not diagnosed early.
e) Vasculitis or inflammation of blood vessels can also lead to stroke.
f) Migraine headaches in a person predisposeato stroke. Certain migraine headaches even mimic symptoms of stroke.
