Intraparenchymal hemorrhage is one form of intracerebral bleeding in which there is bleeding within brain parenchyma. The other form is intraventricular hemorrhage.

Intraparenchymal hemorrhage accounts for approximately 8-13% of all strokes and results from a wide spectrum of disorders. It is more likely to result in death or major disability than ischemic stroke or subarachnoid hemorrhage, and therefore constitutes an immediate medical emergency. Intracerebral hemorrhages and accompanying edema may disrupt or compress adjacent brain tissue, leading to neurological dysfunction. Substantial displacement of brain parenchyma may cause elevation of intracranial pressure (ICP) and potentially fatal herniation syndromes.

Clinical manifestations of intraparenchymal hemorrhage are determined by the size and location of hemorrhage, but may include the following:^{[citation needed]}

In younger patients, vascular malformations, specifically AVMs and cavernous angiomas are more common causes for hemorrhage. In addition, venous malformations are associated with hemorrhage.

In the elderly population, amyloid angiopathy is associated with cerebral infarcts as well as hemorrhage in superficial locations, rather than deep white matter or basal ganglia. These are usually described as "lobar". These bleedings are not associated with systemic amyloidosis.

Hemorrhagic neoplasms are more complex, heterogeneous bleeds often with associated edema. These hemorrhages are related to tumor necrosis, vascular invasion and neovascularity. Glioblastomas are the most common primary malignancies to hemorrhage while thyroid, renal cell carcinoma, melanoma, and lung cancer are the most common causes of hemorrhage from metastatic disease.

Other causes of intraparenchymal hemorrhage include hemorrhagic transformation of infarction which is usually in a classic vascular distribution and is seen in approximately 24 to 48 hours following the ischemic event. This hemorrhage rarely extends into the ventricular system.

Most cases of primary intraparenchymal hemorrhage are the result of chronic hypertension (high blood pressure), cerebral amyloid angiopathy, or both. While these are the causative processes for most cases, a number of other pathological processes are known to accelerate or worsen them, including coagulopathy, vasculitis, brain tumors, ischemic stroke, vascular malformations, and others. In general, diseases and risk factors known to damage blood vessels are considered risk factors, but hypertension and cerebral amyloid angiopathy are particularly strongly associated.