Increased intracranial pressure means the fluid and tissue inside the skull are under too much tension. When the brain is squeezed, warning signs show up fast and tend to pile on top of each other.

The headline symptom is a steady, pounding headache that feels like your head is over-filled. It is usually worse when you lie flat, cough, or bend forward and may wake you from sleep.

Vision blurs next. Lights seem too bright, you see double for a few seconds, or the edges of your sight turn gray. Closing one eye does not clear the blur.

Nausea arrives without stomach flu. You feel queasy and may throw up suddenly—often with no warning and sometimes with relief for a short while.

Thinking slows. You pause mid-sentence, forget why you walked into a room, or mix up today’s date. Family often notices the fog before you do.

Balance drifts. Walking a straight line feels like walking on a mattress; you touch walls or furniture to stay upright.

Later, you may hear an internal “whoosh” that keeps time with your heartbeat, especially at night. Lying flat can make the noise louder, so you start sleeping on extra pillows.