A stroke that is caused by a blood clot is called an ischaemic stroke (is-key-mick). In everyday life, blood clotting is beneficial. Ischemic stroke is the most common type. It is usually caused by a blood clot that blocks or plugs a blood vessel in the brain. This keeps blood from flowing to the brain. Within minutes, brain cells begin to die. Another cause is stenosis, or narrowing of the artery. A stroke is a medical emergency.Symptoms of stroke includes trouble walking, speaking and understanding, as well as paralysis or numbness of the face, arm or leg. They happen when a blood clot blocks the flow of blood and oxygen to the brain. Ischemic stroke is defined as an acute neurological deficit caused by damage to an area in the central nervous system (CNS) as a result of decreased blood flow . Ischemic strokes occur when blood supply is cut off to part of the brain. This type of stroke accounts for the majority of all strokes. Ischemic strokes also include something called a "mini stroke" or a TIA (transient ischemic attack).