Sleep or Sighting Many alien abduction stories happen during sleep or in bedrooms. Experts say some experiences may actually be sleep paralysis mixed with vivid dreams. Why It Feels Real During REM sleep, the brain can generate strong hallucinations and the sense of a presence in the room.

Frozen in Bed Sleep paralysis strikes when your body is asleep but your mind wakes up. You cannot move or speak, and sometimes see or feel strange things. The Science It is caused by REM atonia, which normally keeps you from acting out dreams. Occasionally, your brain wakes up before your body does.

The Body Clock Your body has a built-in clock that runs on a 24-hour cycle, controlling sleep, hormones, and alertness. Why It Matters Disrupted rhythms can cause jet lag, night-shift drowsiness, or even mood swings.

Science Still Guessing No one knows exactly why we dream, though theories range from memory sorting to emotional healing to pure randomness. Dream Recall Most dreams are forgotten within minutes of waking. Keeping a journal can help you remember them longer.

Loud Noises at Night This harmless but startling condition causes you to hear a loud bang or explosion as you are falling asleep or waking up. No Pain, Just Noise Despite the name, nothing actually explodes. Scientists believe it is a glitch in how the brain shuts down for sleep.

Waking in a Dream You dream that you wake up, but are still asleep. Sometimes this happens in layers - dream after dream. How to Spot It Try reading a sentence or flipping a light switch in the dream. Often, things do not work as expected in dream worlds.

Wandering at Night Sleepwalking is more common than you think. About one in 20 adults will sleepwalk at least once. Famous Sleepwalkers Some people have driven cars, cooked meals, or even traveled outside their homes while completely asleep.

The Bedtime Jump A hypnic jerk is that sudden feeling of falling just as you are drifting off to sleep. Nearly everyone gets them sometimes. Theories Some scientists think it is a leftover reflex from our tree-dwelling ancestors, meant to keep us from falling.

Waking Up Wide Awake Insomnia is not just trouble falling asleep. Many people wake up too early and cannot get back to sleep, or spend the night tossing and turning. Why It Happens Causes range from stress and caffeine to hidden medical issues or irregular schedules.

Travel Tiredness Jet lag happens when your body clock gets out of sync with a new time zone. Some people recover quickly, others need days. Not Just Travel Night-shift workers can experience a similar kind of jet lag even if they never leave town.

The Sleeping Beauty Disorder People with this rare condition may sleep up to 20 hours a day for weeks at a time, waking only to eat or use the bathroom. Strange Cycles Episodes come and go, sometimes with months of normal life in between.

Knowing You Are Dreaming A lucid dreamer is aware they are dreaming and can sometimes control the dream world, fly, or do the impossible. How to Try It Keeping a dream journal and doing "reality checks" can help trigger lucid dreams.

Blink and You Miss It Microsleep is when your brain falls asleep for a few seconds, often without you knowing. It can happen when driving, studying, or even in a meeting. Why It Matters Microsleep is a major cause of accidents and errors, especially for tired drivers and workers.

Bad Dreams Nightmares can be caused by stress, medication, fever, or scary stories. Most common in kids, they also trouble many adults. Nightmare Disorders Some people have frequent, intense nightmares that disrupt their sleep and daily life.

Strange Sleep Behaviors Parasomnias include sleepwalking, talking, eating, or even texting while asleep. Science Still Learning Researchers are still unraveling why some brains get so active during sleep.

Acting Out Dreams Normally, your body is paralyzed during REM sleep. In REM Behavior Disorder, people physically act out their dreams and may even get out of bed. Risks This can be dangerous and is often linked to neurological conditions in older adults.

Breathing Stops Sleep apnea causes people to stop breathing briefly during sleep, sometimes hundreds of times a night. Big Consequences It is linked to loud snoring, fatigue, heart disease, and high blood pressure.

No Sleep, Big Problems Going without sleep for even one night can lower your mood, focus, and immune system. Chronic sleep loss is linked to serious health risks. World Record The longest scientifically recorded period without sleep is 11 days. Do not try this at home.

Dreams in Real Life Some people see or hear things that are not there as they fall asleep or wake up. These hallucinations can be vivid and sometimes frightening. Not a Disorder They are surprisingly common and usually harmless unless linked to another sleep problem.

Noisy Nights Snoring happens when air is blocked as it moves through your throat during sleep. It is more common as people age. Not Just Annoying Loud snoring can be a sign of sleep apnea or other health concerns.