What is the normal intracranial pressure range?

• A. 0-5 mm Hg
• B. 5-10 mm Hg
• C. 10-15 mm Hg
• D. 20-25 mm Hg

Answer: (C)

Normal intracranial pressure is kept very low to protect brain perfusion. In adults, the range commonly used in NCLEX-style content is about 10 to 15 mm Hg. This sits comfortably below levels that would impair cerebral blood flow, yet is not so low as to be unrealistic for critically ill or sedated patients. Values higher than this raise concern for intracranial hypertension and potential brain injury; when ICP climbs into the 20s or higher, urgent assessment and intervention are typically needed. So the 10–15 mm Hg range best matches what is considered normal in this context.