That's because the medical word for a clot that forms on a blood-vessel deposit is thrombus. Once in your brain, the clot eventually travels to a blood vessel that's too small for it to pass through. It lodges there, blocking the blood vessel and causing a stroke. The medical word for this type of blood clot is embolus. In a subarachnoid hemorrhage, an aneurysm bursts in a large artery on or near the thin, delicate membrane surrounding the brain.
Blood spills into the area around the brain, which is filled with a protective fluid.
An aneurysm is a weak or thin spot on a blood vessel wall. Aneurysms develop over a number of years and usually don't cause detectable problems until they break. Hypertension is the primary cause of this type of hemorrhage. TIAs are extremely important stroke warning signs. Sioux Valley Hospital USD Medical Center.