Hypertensive encephalopathy happens when blood pressure shoots so high that the brain’s normal flow gets scrambled. Symptoms build fast—often over hours—and can reverse just as quickly once pressure is lowered.

The lead complaint is a pounding headache that feels like the head is over-inflated. It is usually on both sides, throbs in time with the heartbeat, and is worse when lying flat.

Vision blurs next. Lights seem too bright, edges of the room gray out, or you see brief double that clears when you cover one eye.

Nausea and vomiting hit without stomach upset. The urge is sudden and may repeat several times in an hour.

Thinking slows or slips. You pause mid-sentence, forget why you walked into a room, or hear family say you’re “not making sense.”

Balance drifts. Walking feels like treading on a waterbed; you touch walls or furniture to stay upright.

Some people hear an inside “whoosh” matching their pulse, especially at night. Extra pillows often turn the volume down.

If pressure keeps climbing, drowsiness deepens and seizures or brief blackouts can appear—an emergency signal.