Background: Stroke is a heterogenic group of disorders. Cerebral infarction is the largest group (80-85%) and is followed by primary intracerebral hemorrhage and subarachnoid hemorrhage. This article gives a review of risk factors for cerebral stroke, with an emphasis on cerebral infarction.
Material and methods: The article is based on literature identified through Medline, with emphasis on prospective, population-based studies.
Results and interpretation: Genetic studies of the Icelandic population have shown associations between single genes and common types of stroke, but it remains to be seen whether the results can be replicated in other populations. High blood pressure and cigarette smoking are the most important modifiable risk factors for stroke. Serum cholesterol is positively associated with cerebral infarction, but not with intracerebral hemorrhage. Diabetes, atrial fibrillation and carotid stenosis are important predictors of cerebral infarcts, especially in the elderly. Cohort studies and randomized trials have shown that hormone replacement therapy in women increases the risk of stroke, while modern oral contraceptives do not represent a risk factor for stroke in young women. There is a clear social gradient in stroke occurrence, with a higher incidence in lower social classes.