Increased intracranial pressure

The adult cranial cavity is a relatively closed space, with the rigid skull forming an outer wall that gives this space a fixed volume (approximately 1400-1700 mL), unable to expand or contract like a balloon. The contents of the cranial cavity primarily include brain parenchyma (approximately 80%), blood (approximately 10%), and cerebrospinal fluid (approximately 10%). Increased intracranial pressure (ICP) refers to a significant elevation in intracranial pressure due to brain tissue pathology or excessive cerebrospinal fluid, which may lead to compression of surrounding nerves and blood vessels. It is more common in middle-aged and elderly individuals. Main symptoms include dizziness, headache, fatigue, somnolence, nausea, vomiting, tinnitus, hearing or vision impairment, slow reactions, abnormal behavior, and difficulty walking or speaking normally.