Which of the following is a critical sign of increased intracranial pressure?

A critically important sign of increased intracranial pressure (ICP) is increasingly severe headache. When ICP rises, the pressure within the skull increases, which can lead to a variety of symptoms reflecting the brain's response to this situation. A severe headache that worsens over time is often a direct result of the increased pressure on brain structures, leading to irritation of pain-sensitive areas.

Severe and worsening headaches, especially those that may wake a person from sleep or are unrelieved by usual pain medications, can indicate significant pathology. This could include conditions such as brain tumors, hemorrhage, or traumatic brain injury, all of which can lead to elevated ICP. Thus, recognizing increasingly severe headaches as a critical sign allows for timely intervention to address the underlying cause and prevent potential complications.

Visual disturbances may also occur in the context of increased ICP but are often not as immediate or concrete as a progressively severe headache. An increased appetite does not typically correlate with increased ICP; in fact, patients might have a reduced appetite or nausea due to increasing pressure. Rapid heartbeat could arise from a multitude of causes, including anxiety or physiological stress responses, but does not directly indicate increased ICP.