Hypnagogic and hypnopompic hallucinations

Hypnagogic experiences happen as you fall asleep. Hypnopompic ones happen as you wake. Both are common, both are normal, and neither indicates a psychiatric condition.

What people report

• Geometric patterns, faces or scenes while drifting off.
• A voice saying their name, once, clearly, close by.
• A sudden loud bang or crash with no source. This has its own name, exploding head syndrome, and despite the alarming label it is harmless.
• A sensation of falling, often with a jolt (a hypnic jerk).

Why they happen

At the boundary between wake and sleep, sensory processing and reality-monitoring are both in flux. Internally generated imagery gets through without being tagged as internal.

The bit worth saying plainly

A lot of people have these and quietly assume something is wrong with them. It is not.

The distinction that does matter: experiences only at the edge of sleep are this phenomenon. Hallucinations while fully awake and alert are something different and worth discussing with a doctor. That is not a reason for alarm. It is a reason to be clear about which one you are having.

Frequency

They increase with sleep deprivation and irregular schedules, which is the actionable part and is trackable in the sleep log.