The causes of a massive stroke include a blood clot lodged in an artery in the brain, a blood clot that forms somewhere else in the body and travels to the brain, and the rupture of a blood vessel in the brain, according to Mayo Clinic.
How massive the stroke is depends on how long the brain was deprived of oxygen, according to Mayo Clinic.
Strokes caused by blood clots are ischemic strokes, claims Mayo Clinic. A blood clot that originates in the brain is called a thrombus, while a blood clot that travels from a distant site in the body is called an embolus. Plaque buildup in arteries and other arterial conditions can cause clots that lead to stroke.
The rupture of blood a vessel in the brain is called a hemorrhagic stroke, says Mayo Clinic. There are several types. Intracerebral hemorrhage happens when a blood vessel within the brain bursts. This damages brain cells directly and causes other cells to be starved of oxygen. Subarachnoid hemorrhage occurs when an artery that is on or near the surface of the brain ruptures. The blood then floods the area between the brain and the skull. This type of stroke is often caused when an aneurysm, a weakened, distended area in an artery wall, bursts.