The document discusses cerebrovascular diseases, which are abnormalities of the brain caused by pathologies of blood vessels. It describes the main categories of cerebrovascular diseases including thrombosis, embolism, hemorrhage and strokes. It then focuses on hypoxia, ischemia and infarction resulting from impaired blood supply as well as hemorrhages from ruptured vessels. Specific conditions discussed include global and focal cerebral ischemia, infarction, intracranial hemorrhages, vascular malformations and hypertensive cerebrovascular disease.