Brain bleeds (intracranial hemorrhages) are caused by bleeding within or around the brain due to a rupture or limited clotting. The most common triggers include high blood pressure, head trauma, and problems with blood vessels or clotting. Below is a concise map of key causes and related factors. Core causes

• Head trauma or injury: Falls, motor vehicle accidents, sports injuries, and other impacts can rupture blood vessels in or around the brain. This is a leading cause in younger adults and athletes.

• Hypertension (high blood pressure): Chronic high blood pressure weakens vessel walls, increasing the risk of spontaneous bleeds, especially inside the brain tissue (intracerebral hemorrhage).

• Aneurysm rupture: An aneurysm is a weakened, bulging area in a vessel wall that can rupture and spill blood into surrounding brain spaces, commonly causing subarachnoid hemorrhage.

• Vascular malformations: Abnormal connections between arteries and veins (such as arteriovenous malformations, AVMs) or other vessel abnormalities can rupture and bleed.

• Cerebral amyloid angiopathy (CAA): Amyloid deposits in vessel walls, more common with aging, heightening the risk of lobar hemorrhages.

• Blood disorders and medications: Conditions that impair clotting (e.g., hemophilia, thrombocytopenia) or the use of anticoagulant/antiplatelet therapies raise bleeding risk. Liver disease can also affect coagulation.

• Brain tumors: Some tumors bleed due to abnormal or fragile tumor vessels.

• Alcohol and illicit drugs: Acute rises in blood pressure from substances like alcohol or cocaine can precipitate a bleed.

• Other medical conditions: Severe liver disease, septic processes, or pregnancy-related complications (e.g., eclampsia) can contribute to intracranial bleeding in specific contexts.

Less common or context-specific factors

• Age-related vessel changes: Aging vessels may become more fragile, particularly in the presence of hypertension or CAA, increasing spontaneous risk.

• Coexisting conditions: Diabetes, migraines with vascular components, or connective tissue disorders may play a contributory role in some cases.

What this means for prevention and recognition

• Risk management: Controlling blood pressure, avoiding and treating aneurysms or AVMs when identified, limiting alcohol and illicit drug use, and safely managing blood thinners under medical supervision can reduce risk.

• Symptoms to watch for: Sudden severe headache, weakness or numbness on one side, confusion, difficulty speaking, trouble with vision, loss of balance, or loss of consciousness—these require urgent medical evaluation.

If you’d like, I can tailor this to a specific context (such as adult risk factors, elderly risk, or guidance for someone with a known AVM or aneurysm) or provide a quick comparison of the most common causes with their typical presentations.