Experiencing realistic, intense, and disturbing dreams right before you wake up is a phenomenon known as “hypnopompic hallucinations.”
About 8 percent of people 15 to 44 reported experiencing these, a Stanford University study found.
You feel like you’re still asleep during these episodes, but you’re actually in the transitional time between sleep and wakefulness.
Because you’re not actually asleep when they occur, these “dreams” aren’t dreams at all—that’s why they’re officially referred to as hallucinations.
Your brain is in a semi-awake/semi-asleep state: Part of it is still in rapid eye movement, or REM, sleep—the deep stage of sleep where our brain is more active, allowing for intense dreams.As you begin to rouse, the dream-like imagery of REM sleep intrudes into your waking state. This causes you to experience the hallucinations.
Hypnopompic hallucinations can be visual (you “see” a scene or situation in your mind), auditory (you think you hear something, like a knock on the door or someone calling your name), or tactile (you feel like something is touching you, such as a spider crawling over your skin).
You can experience this in regular dreams when you are sleeping, too. But because these hallucinations seem so vivid, they can seem especially disturbing and frightening.
While anyone can experience hypnopompic hallucinations, they are more common in people who spend more time in REM sleep.
This can be due to sleep deprivation, certain medications like tricyclic antidepressants, or even sleep disorders like narcolepsy.
Many people experience vivid hypnopompic hallucinations along with the sleep paralysis—a condition in which you’re fully conscious, but unable to speak or move upon waking—which can make the experience even scarier. Sleep paralysis affects up to 5 percent of the population.
You can try to cut down on the hypnopompic hallucination episodes by reducing your risk factors for them—namely, sleep deprivation. That means maintaining a more regular sleep cycle and making sure to sleep a solid 7 to 8 hours each night.
Not all hypnopompic hallucinations need to be treated by a professional.
But in my practice, those that occur frequently—say, 3 or 4 times a week—and are distressing enough to impair the person’s sleep quality or daytime function should be evaluated and managed.
If your hypnopompic hallucinations are hitting that benchmark—especially if you feel really sleepy during the day—you should make an appointment with your doctor.In those cases, they may be signaling a more serious condition, like narcolepsy.