Circadian rhythm disorders
Advanced Sleep-Wake Phase Disorder
Your body clock runs early, making you very sleepy in the early evening and waking you in the small hours. It is more common in older adults.
Overview
Advanced sleep-wake phase disorder (ASWPD) is the opposite of delayed sleep phase. Your internal clock is set earlier than desired, so you become sleepy in the early evening, often between 6 and 9 p.m., and wake very early, sometimes between 2 and 5 a.m.
If you stay up later to match social plans, you still tend to wake early, which leads to short sleep and daytime tiredness. ASWPD is more common with age, and some families carry gene variants that cause it.
It is sometimes mistaken for insomnia or depression because of early waking. Carefully timed evening light can help move the clock later.
Common symptoms
- Strong sleepiness in the early evening
- Waking very early and being unable to return to sleep
- Normal sleep length when going to bed early
- Short sleep and daytime tiredness when staying up later
- Difficulty staying awake for evening social or family activities
Causes and risk factors
- Older age
- Inherited forms linked to circadian clock gene variants
- Lack of evening light exposure
- Being a natural early riser (strong morning chronotype)
How it is diagnosed
Diagnosis uses your sleep history plus at least 7 days, preferably 14, of sleep diary and actigraphy showing a stable, early sleep pattern. Clinicians also check for early-morning waking caused by depression, sleep apnea or other conditions.
Treatment options
Evening bright light
Light exposure in the evening can delay the body clock. AASM guidance suggests light therapy for ASWPD.
Avoiding early-morning light
Wearing sunglasses or keeping the bedroom dark if awake early.
Gradual schedule adjustment
Staying up a little later step by step.
What you can do yourself
- Spend time in bright light in the late afternoon and evening
- Keep the bedroom dark in the early morning
- Plan engaging activities in the evening to stay awake
- Avoid long naps in the late afternoon
When to see a doctor
- Early waking is causing persistent tiredness
- You also feel low, lose interest or have appetite changes
- You snore or have breathing pauses
Frequently asked questions
Is waking at 4 a.m. normal as you age?
Sleep timing often shifts earlier with age, but very early waking that leaves you tired, or that comes with low mood, is worth discussing with a clinician.
How is ASWPD different from insomnia?
With ASWPD you sleep well if you go to bed early; the timing is simply early. In insomnia, sleep is difficult regardless of when you go to bed.
How do I use light to fix it?
Bright light in the evening helps shift the clock later. Clinicians may recommend a light box at a specific time each evening.
Can it run in families?
Yes. Familial advanced sleep phase is linked to variants in clock genes, and several family members may share very early sleep times.
Sources
This page is general information, not a diagnosis or medical advice. Read our medical disclaimer.