A second major cause of stroke is bleeding in the brain. This is called a hemorrhagic stroke. It can occur when small blood vessels in the brain become weak and burst. Some people have defects in the blood vessels of the brain that make this more likely. The flow of blood that occurs after the blood vessel ruptures damages brain cells.
Hemorrhagic stroke is most often due to high blood pressure, which stresses the artery walls until they break.
Other causes of hemorrhagic stroke include:
- Aneurysms, which create a weak spot in an artery wall that can eventually
- Abnormal connections between arteries and veins, such as an arteriovenous
- Cancer, particularly cancer that spreads to the brain from distant organs
such as the breast, skin, and thyroid
- Cerebral amyloid angiopathy, a build up of amyloid protein within the artery
walls in the brain, which makes bleeding more likely
- Conditions or medications (such as aspirin or Warfarin) that can make you
- Illicit drugs, such as cocaine
An aneurysm is a sac-like protrusion of an artery caused by a weakened area within the vessel wall. If a cerebral (brain) aneurysm ruptures, the escaping blood within the brain may cause severe neurologic complications or death. A person who has a ruptured cerebral aneurysm may complain of the sudden onset of "the worst headache of my life."
Occurs when a burst blood vessel bleeds into the brain, causing brain cells to die
Intracerebral hemorrhage may be caused by trauma (brain injury) or abnormalities of the blood vessels (aneurysm or angioma). When it is not caused by one of these conditions, it is most commonly associated with high blood pressure (hypertensive intracerebral hemorrhage).
Occurs when a blood vessel bursts near the surface of the brain and blood pours into the area between the brain and skull. The event may increase pressure in the brain, injuring brain cells. Subarachnoid hemorrhage can be caused by:
- Bleeding from an arteriovenous malformation (AVM)
- Bleeding disorder
- Bleeding from a cerebral aneurysm
- Head injury
- Unknown cause (idiopathic)
- Use of blood thinners
Injury-related subarachnoid hemorrhage is often seen in the elderly who have fallen and hit their head. Among the young, the most common injury leading to subarachnoid hemorrhage is motor vehicle crashes.
Subarachnoid hemorrhage due to rupture of a cerebral aneurysm occurs in approximately 10-15 out of 10,000 people. Subarachnoid hemorrhage due to rupture of a cerebral aneurysm is most common in persons age 20 to 60. It is slightly more common in women than men.
- Aneurysms in other blood vessels
- Fibromuscular dysplasia (FMD) and other connective tissue disorders associated
with aneurysm or weakened blood vessels
- High blood pressure
- History of polycystic kidney disease
- A strong family history of aneurysms may also increase your risk.