Abnormally high pressure within the skull is known as:

Abnormally high pressure within the skull is known as Increased intracranial pressure

Increased intracranial pressure is an abnormal rise in the pressure inside the skull that can result from or cause brain injury. It can be due to a rise in pressure of the cerebrospinal fluid (CSF). CSF is the fluid that surrounds the brain and the spinal cord. It can also be due to a rise in pressure within the brain itself. Presence of a mass (such as a tumor), bleeding into the brain or fluid around the brain, and swelling within the brain can also cause increased intracranial pressure.