OBJECTIVE: To determine the etiologies and risk factors of intracerebral hemorrhage in young people.
 Methods: A total of 401 young patients with intracerebral hemorrhage were enrolled, and they were assigned into a 20-29 , a 30-39, and a 40-45 age group. The differences of various etiologies and risk factors among the three groups were analyzed.
 Results: There were 273 men and 128 women in the 401 young patients. The etiologies of 294 patients (73.32%) were identified while 107 patients (26.68%) were unknown. Among those with identified etiology, 226 patients (56.36%) suffered from hypertension, 41 patients (10.22%) congenital cerebrovascular malformation (including 25 patients with cerebral arteriovenous malformation, 8 intracranial cavernous hemangioma, and 8 intracranial aneurysm), and 27 other etiologies (including 9 patients with moyamoya disease, 6 cerebral venous sinus thrombosis, 4 drug abuse, 3 hemorrhagic brain tumor, 2 intracranial infection, 1 systemic lupus erythematosus, 1 drug-induced, and 1 eclampsia). Risk factors included hypertension (237 cases, 59.10%), smoking (123 cases, 30.67%), alcohol consumption (74 cases, 18.45%), and others (19 cases, 4.74%; including 8 cases of pregnancy or in the puerperium, 8 family history of intracerebral hemorrhage, and 3 taking anti-platelet aggregation/anticoagulation agents). The rate of hypertension induced hemorrhage significantly increased with age (P<0.01); the rate of vascular malformations in 20-29 age group was obviously higher than other groups (P<0.01); the rate of unknown cause in the 40-45 age group was significantly lower than other groups (P<0.01) and the rate of other etiologies showed no significant difference in the 3 groups. The rate of hypertension was significantly elevated with the age (P<0.01), while smoking, alcohol consumption, and other risk factors showed no significant difference in the 3 groups.
 Conclusion: The rate of intracerebral hemorrhage in young people increases with the increasing of age and hemorrhage affects men more than women; hypertension may be the main cause and congenital cerebrovascular malformation is the second cause, which may be more common in younger patients. Hypertension, smoking, and alcohol consumption may be the major controllable risk factors in intracerebral hemorrhage in young people.