Why are sleep difficulties are common in autistic people?
Autistic people often have sleep problems. Research suggests this affects between 50% and 80% of autistic people. There is no single reason for this. Each autistic person is different, so sleep support needs to be individual.
Differences in sleep regulation and biology
- Many autistic people find it hard to fall asleep, stay asleep, or wake at a consistent time.
- The body clock (circadian rhythm) may not match the outside world.
- The brain can take longer to switch into “sleep mode”.
- Some autistic people naturally fall asleep later or wake earlier.
Example:
An autistic adult may lie awake for hours, even when they feel tired. This is not laziness or a “bad habit”. It is a biological difference.
Sensory processing differences
Sensory needs can affect sleep.
- Noise (even small sounds) can wake someone up.
- Light, LED glow, or streetlights can disturb sleep.
- Bedding textures, temperature, smells, or clothing can be uncomfortable.
- Some autistic people seek deep pressure or movement before sleep.
Example:
A child may not settle if their pyjamas feel “wrong”. An adult may wake up every time the heating switches on.
Linked health conditions
Some medical conditions are more common in autistic people.
- Sleep apnoea
- Restless legs syndrome
- Gastrointestinal pain
- Epilepsy
- Anxiety
Example:
An autistic person with reflux may wake because lying flat is uncomfortable.
Circadian rhythm differences
The circadian rhythm is the body’s internal 24‑hour clock.
- It controls when we feel awake or sleepy.
- It affects hormones like melatonin (helps you sleep) and cortisol (keeps you alert).
- Many autistic people have a delayed or irregular body clock.
Example:
A teenager may naturally fall asleep at 2am and wake at 11am, even with a routine.
Emotional and cognitive differences
- Anxiety or fear can make it hard to relax.
- Some autistic people find it hard to “switch off” their thoughts.
- Dreams may feel intense or frightening.
- A need for predictability can make bedtime feel stressful if the routine changes.
Understanding hormones and sleep
Hormones affect sleep at different times in life.
Melatonin
- Helps the body feel sleepy.
- Released when it gets dark.
- Autism can affect how much melatonin is released and when.
Cortisol
- Keeps us awake and alert.
- Highest in the morning, lowest at night.
- Stress, illness, fear, or pain increase cortisol.
- High cortisol blocks melatonin, making sleep harder.
Hormone changes across life
These changes can affect autistic people more strongly:
Puberty
- Body changes can increase anxiety.
- Melatonin release shifts later, so many young people fall asleep later.
Menstrual cycle
- Some autistic people feel more pain or sensory discomfort during periods.
- Hormones can cause disrupted sleep on certain days.
Menopause
- Hot flushes, night sweats, sensory discomfort, and anxiety can disturb sleep.
- Many autistic adults report worsening sleep during menopause.
Testosterone changes
- Hormone changes in adulthood can influence tiredness, mood, and sleep rhythm.
What happens when we do not get enough sleep?
Lack of sleep affects mental, emotional, and physical health.
Thinking and learning
- Harder to concentrate
- Forgetfulness
- Slower thinking
- Difficulty learning new tasks
Emotions and behaviour
- Irritability
- Low mood
- Feeling overwhelmed
- Emotional outbursts
- “Hyper” or overactive behaviour (especially in children)
Physical health
- Lower immunity
- Slower recovery from illness
- Low energy
- Appetite changes
- For children: possible impact on growth
Example:
A tired child may seem “wired” or overactive, but this is because their brain is exhausted.
Key points to remember
- Sleep difficulties are very common in autistic people.
- Sensory needs, biology, and emotions all play a role.
