Unusual sleep behaviors are common and often harmless, especially when they occur during deep sleep phases.

Parasomnias include sleepwalking, night terrors, REM sleep behaviour disorder, teeth grinding, and sleep talking.

Some sleep phenomena can be dangerous and may signal neurological or psychological conditions.

Stress, poor sleep quality, and sleep disruption increase the likelihood of abnormal night-time behaviors.

Supporting the nervous system through routine, relaxation, and gut health may improve sleep quality.

In This Article:

• Why Sleep Behavior Can Appear Unusual or Disturbed
• What Parasomnias Are and How They Affect Sleep
• What Causes Sleep Drunkenness After Waking From Deep Sleep
• Why Sleepwalking Can Be Dangerous
• What REM Sleep Behavior Disorder Is and Why It Matters
• How Nightmares Are Linked to Emotional Stress
• Why Sudden Body Twitching Occurs When Falling Asleep
• What Causes Teeth Grinding During Sleep (Bruxism)
• Why Some People Talk in Their Sleep
• When Sleep-Related Behaviors Require Medical Advice
• How Supporting the Nervous System Can Improve Sleep Quality

Why Sleep Behavior Can Appear Unusual or Disturbed

Sleep looks peaceful from the outside, but the brain remains highly active throughout the night. While consciousness fades, movement control, memory, and emotional processing continue in complex ways.

That’s why some people:

• Talk, shout, or argue
• Grind their teeth
• Jerk suddenly while falling asleep
• Walk, eat, or perform tasks
• Wake confused or disoriented

Often, they remember nothing the next morning.

What Parasomnias Are and How They Affect Sleep

Parasomnias are abnormal behaviours that occur during sleep or while transitioning between sleep stages. According to Dr. Peter Geisler, Head of the Sleep Medicine Center at Regensburg District Hospital, these behaviours can reduce sleep quality and sometimes pose safety risks.

Short-term memory is largely inactive during sleep, which explains why most people don’t remember what they did overnight.

What Causes Sleep Drunkenness After Waking From Deep Sleep

Sleep drunkenness (also called confusional arousal) occurs when a person wakes from deep sleep but the brain doesn’t fully switch on.

Symptoms include:

• Confusion and slow speech
• Disorientation
• Odd or inappropriate actions
• No memory of the episode

It’s common in children and usually harmless. In adults, it may overlap with sleepwalking tendencies.

Why Sleepwalking Can Be Dangerous

Sleepwalking occurs during deep sleep, usually in the first third of the night. People may:

• Wander through the house
• Speak nonsensically
• Cook or leave the home
• Injure themselves

Up to 20% of sleepwalkers are injured. Contrary to myths, sleepwalking is not safe or graceful.

Important safety tips:

• Lock doors and windows at night
• Do not wake a sleepwalker abruptly
• Speak calmly and guide them back to bed

What REM Sleep Behavior Disorder Is and Why It Matters

REM sleep behaviour disorder causes people to physically act out dreams. Movements may include kicking, punching, or jumping out of bed.

This condition:

• Occurs mainly in older men
• Can injure both the sleeper and their partner
• Is linked to dysfunction in the brainstem
• May be an early warning sign of Parkinson’s disease

Anyone experiencing this should see a neurologist.

How Nightmares Are Linked to Emotional Stress

Nightmares affect around 5% of adults regularly. They usually occur in REM sleep and cause the person to wake fully, remembering the dream clearly.

Triggers include:

• Stress and trauma
• Anxiety or depression
• Certain medications

A proven technique called imagery rehearsal therapy involves rewriting the nightmare ending and practicing it daily. Controlled studies show strong effectiveness.

Why Sudden Body Twitching Occurs When Falling Asleep

Sudden jerks or “electric shock” sensations while drifting off are called hypnic jerks. They are usually harmless and occur when the brain and muscles relax at different speeds.

However, frequent limb twitching may signal restless legs syndrome and should be medically assessed.

What Causes Teeth Grinding During Sleep (Bruxism)

Teeth grinding or clenching (bruxism) often goes unnoticed until:

• Jaw or head pain appears
• Teeth show wear
• Dental issues develop

Causes include stress, anxiety, and dental misalignment. Dentists can help prevent long-term damage.

Why Some People Talk in Their Sleep

Sleep talking ranges from mumbling to full sentences. It’s common and usually harmless.

Possible triggers:

• Stress
• Fever
• Alcohol
• Emotional processing during dreams

Experts believe it may be related to mild sleepwalking tendencies.

When Sleep-Related Behaviors Require Medical Advice

Professional support is recommended if:

• Behaviors are frequent or violent
• Injuries occur
• Daytime fatigue increases
• Symptoms worsen with time

A GP or sleep specialist can rule out neurological, psychological, or breathing-related causes.

How Supporting the Nervous System Can Improve Sleep Quality

Healthy sleep depends on a calm and balanced nervous system. Supporting digestion and detoxification may indirectly support sleep quality.

Colonic hydrotherapy can help by:

• Reducing physical stress in the gut
• Supporting nervous system regulation
• Promoting overall relaxation and sleep readiness