Normal intracranial pressure is considered to be less than which value?

Normal intracranial pressure is considered to be less than which value?

• A. Less than 5 mm Hg
• B. Less than 10 mm Hg
• C. Less than 15 mm Hg
• D. Less than 20 mm Hg

Answer: (C)

Normal intracranial pressure is the pressure inside the skull that maintains cerebral perfusion while avoiding harmful distention. In adults, this upper limit is about 15 mm Hg; values below this are considered normal. The brain can compensate for small increases through shifting CSF and venous outflow, but once ICP gets near this threshold, compensatory mechanisms become exhausted and any further rise threatens cerebral perfusion. Therefore, the threshold used in exams is that normal ICP is less than 15 mm Hg. Values above this, especially around 20 mm Hg or higher, are considered intracranial hypertension and require intervention.

Normal intracranial pressure is the pressure inside the skull that maintains cerebral perfusion while avoiding harmful distention. In adults, this upper limit is about 15 mm Hg; values below this are considered normal. The brain can compensate for small increases through shifting CSF and venous outflow, but once ICP gets near this threshold, compensatory mechanisms become exhausted and any further rise threatens cerebral perfusion. Therefore, the threshold used in exams is that normal ICP is less than 15 mm Hg. Values above this, especially around 20 mm Hg or higher, are considered intracranial hypertension and require intervention.