What is the normal intracranial pressure (ICP) range?

• A. 0-15 mm Hg
• B. 0-10 mm Hg
• C. 5-15 mm Hg
• D. 10-20 mm Hg

Answer: (A)

Normal intracranial pressure is the pressure inside the skull that maintains brain perfusion without causing compression. In adults, the typical normal range is about 0 to 15 mm Hg. This upper limit is important because sustained ICP above roughly 20 mm Hg suggests intracranial hypertension and may require intervention. Values below zero aren’t physiologic, and ranges that cap lower or higher values would miss the normal spread. Therefore, 0-15 mm Hg best reflects a normal ICP range.