Strokes occur when blood vessels in the brain leak or burst, when arteries become blocked or when blood flow to the brain is temporarily disrupted, according to Mayo Clinic. Medical issues including high cholesterol, diabetes, cardiovascular disease, obesity or sleep apnea increase the risk of having a stroke, reports WebMD.
A intracerebral or subarachnoid hemorrhage, both classified as hemorrhagic strokes, may occur when blood vessels leak or break open. During a hemorrhagic stroke, blood may saturate brain tissue, or settle in the space between the brain and skull. The causes of hemorrhagic stroke include the overuse of blood thinning medications, high blood pressure and physical trauma, states Mayo Clinic.
When arteries in the brain become obstructed by blood clots, thrombotic or embolic strokes, also known as ischemic strokes, may occur, states Mayo Clinic. High cholesterol, smoking and other tobacco use, diabetes and obesity contribute to the formation of blood clots, states WebMD. About 85 percent of strokes that occur are ischemic strokes, according to Mayo Clinic. A ministroke, also known as a transient ischemic attack, may temporarily stop blood flow to the brain. Transient ischemic attacks are also typically caused by blood clots and may last up to 5 minutes, reports May Clinic.