Bleeding in the brain, what doctors call hemorrhagic stroke, is a potentially life-threatening condition. The rupture of a blood vessel interrupts blood supply to some brain cells. Other cells are damaged by pressure--since the skull cannot swell to accommodate the spilling blood, bleeding compresses brain tissues, which can destroy brain cells. The brain does not regenerate damaged cells, so brain functions lost due to stroke may never be recovered. Some hemorrhagic strokes are triggered by unavoidable conditions, but many of the risk factors that contribute to bleeding in the brain are controllable.
High Blood Pressure
High blood pressure, or hypertension, is the single most important risk factor for bleeding in the brain. The National Stroke Association estimates that it causes about 60 percent of all cases of hemorrhagic stroke. Blood vessels first form bulging areas with weak walls, known as aneurysms. The vast majority of hemorrhagic strokes are burst aneurysms. Aneurysms form in patients with high blood pressure, and aneurysms are more likely to burst when the blood flowing through them is under high pressure. Healthy, normal blood vessels rarely ever rupture. Hypertension is affected by diet and exercise and is controllable with medications if other methods fail.
Abuse of Alcohol or Drugs
Researchers have connected heavy alcohol consumption and drug use to an increased risk of hemorrhagic stroke, particularly in young people. According to the American Stroke Association, people in their 20's and 30's may account for 90 percent of all drug-related brain bleeds.
Smoking
Smokers have an increased risk of hemorrhagic stroke. Patients who find themselves unable to quit smoking can reduce their risk if they can simply reduce the amount they smoke.
Anti-Clotting Medications
Patients on certain anti-clotting medications face an increased risk of bleeding in the brain. Doctors face a dilemma in prescribing these medicines, since they may actually prevent ischemic stroke, in which a blood clot blocks blood flow to part of the brain, but no vessel bursts. Because blood thinners require careful balancing to reduce ischemic stroke risk without increasing the risk of bleeding, patients on blood thinners must work with their doctors to track their medication levels constantly.
Blood-Clotting Disorders
Certain blood-clotting disorders, such as hemophilia and sickle-cell anemia, make a hemorrhagic stroke more likely. Large clots in the blood can cause a blood vessel to swell, forming an aneurysm, which may burst. Patients with clotting disorders should monitor their blood pressure closely.
Brain Vascular Malformation
Some people are born with a small cluster of abnormally formed arteries and veins inside the brain. Because these vessels are abnormal, they may be weaker than normal vessels and can rupture. An arteriovenous malformation, or AVM, is a rare occurrence; the American Stroke Association estimates that as few as one in every 500 people may have one, and that AVMs are more common in men than in women. Not all AVMs will rupture; many people may live their entire lives with an AVM and never experience any symptoms. But the American Stroke Association estimates that, over a 15-year period,
there is a 25 percent chance that an AVM will rupture. Patients who are diagnosed with an AVM will need to monitor their blood pressure carefully for the rest of their lives to control their risk.
