Epidural hemorrhage can be broken down. "Epi" means above, "dural" refers to the outermost protective layer of the brain, which is called dura mater and and “hemorrhage” refers to bleeding.
So, an epidural hemorrhage is when there’s bleeding above the dura mater.
OK - let’s start with some basic brain anatomy. The brain is protected by the meninges, which are 3 thin layers of tissue which cover the brain and spinal cord.
The inner layer of the meninges is the pia mater, the middle layer is the arachnoid mater, and the outer layer is the dura mater.
The pia and arachnoid maters, are also called leptomeninges.
Between the leptomeninges, there’s the subarachnoid space, which houses cerebrospinal fluid, or CSF.
CSF is a clear, watery liquid which is pumped around the spinal cord and brain, cushioning them from impact and bathing them in nutrients.
The outer membrane, the dura mater consists of two layers.
The internal layer of the dura mater lies above the arachnoid mater - the two are separated by the subdural space.
The external layer of the dura mater adheres to the inner surface of the skull.