An increase in normal brain pressure can be due to an increase in cerebrospinal fluid pressure. It can also be due to increased pressure within the brain matter caused by lesions (such as a tumor) or swelling within the brain matter itself.

An increase in your intracranial pressure is a severe medical problem. The pressure itself can be responsible for further damage to the central nervous system by causing compression of important brain structures and by restricting blood flow through blood vessels that supply the brain.

Many conditions can increase intracranial pressure. Common causes include:

• severe head injury
• subdural hematoma
• hydrocephalus
• brain tumor
• hypertensive brain hemorrhage
• intraventricular hemorrhage
• meningitis
• encephalitis
• aneurysm rupture and subarachnoid hemorrhage
• status epilepticus
• stroke

Infants:

• bulging fontanelle
• separated sutures
• lethargy
• vomiting

• vomiting
• headache
• changes in behavior
• progressive decreased consciousness, lethargy
• neurologic deficits
• seizures

A diagnosis of raised intracranial pressure is made at the patient's bedside. An MRI or CT scan is often used to determine the cause and confirm the diagnosis.

Intracranial pressure is measured in millimeters of mercury (mm Hg). Intracranial pressure may be measured during a spinal tap (lumbar puncture). It may also be measured directly by a calibrated device. This device is drilled through the skull to measure the pressure on the surface of the brain, or a catheter is inserted to allow it to measure the pressure inside the brain.