Brain bleeds (Intracranial Hemorrhages, ICH) can be classified based on the brain compartment involved and the cause:

1- Bleeding into brain tissue (Hemorrhagic stroke, Intracerebral hemorrhage, Intraparenchymal hemorrhage, IPH): the most common type, mostly due to small vessel diseases of the brain in older adults but many less common causes exist. Most common small vessel disease related hemorrhages are:

       Hypertensive Brain Bleeds

       Cerebral Amyloid Angiopathy (CAA)

2- Primary Intraventricular Hemorrhage: bleeding inside the ventricles, i.e. spinal fluid containing spaces in the brain

3- Bleeding inside the coverings of the brain

        Subarachnoid hemorrhage (SAH) -> 85% related to aneurysms (balooning) of brain arteries

        Subdural hemorrhage (SDH) -> either related to trauma OR "chronic, spontaneous" in older adults

        Epidural hemorrhage (EDH) -> mostly related to trauma, rare but very severe type

4- Smaller hemorrhagic pathologies visible especially on brain MRI

        Microbleeds -> very small amount of "oozing" from the small vessels of the brain, visible on special                                     MRI sequences (SWI or GRE) 

        Superficial siderosis -> small layer of very superficial bleeding, visible on MRI, mostly seen in CAA

 5- Other, non-bleeding pathologies that might signal a higher risk of brain bleeding

         White matter disease -> probably related to inadequate flow to deeper brain regions, related to                                                            the small vessel diseases that also cause bleeding (CAA, hypertensive)

          Lacunar infarcts -> small deep infarcts that commonly cause stroke symptoms (3-15mm diameter)