The vast majority of unprovoked (non-traumatic) cerebral hemorrhages are caused by hypertension, as hypertension leads to gradual changes in artery size and shape, weakening of artery walls, aneurysm formation, and eventual rupture. Other less common causes of cerebral hemorrhage include a degenerative disorder of the small vessels called amyloid angiopathy (particularly in older patients), vessel abnormalities such as arteriovenous malformations or cavernous malformations (usually seen in young patients), aneurysms, certain tumors, and abscesses. Drug abuse with substances such as cocaine can also cause cerebral hemorrhage, as can some medications commonly prescribed by doctors. These medications include tPA that is given for patients with acute arterial blockages, warfarin that is used to prevent or treat clots, and even (rarely) aspirin or related drugs such as clopidogrel, ticlopidine, and dipyridamole.

The best available medical "treatment" is prevention of a cerebral hemorrhage before it occurs. Treating hypertension, decreasing illegal drug use, and prescribing medications carefully with close patient monitoring may decrease the frequency of cerebral hemorrhages.