Circadian rhythm disorders
Shift Work Disorder
Insomnia and excessive sleepiness caused by working nights, early mornings or rotating shifts that clash with your body clock.
Overview
Shift work disorder affects people whose work hours overlap with their usual sleep time, such as night shifts, early morning starts or rotating schedules. Your body clock still tells you to sleep at night and be awake during the day, so you may struggle to sleep after a night shift and feel very sleepy at work.
Not every shift worker develops the disorder, but many do. Daytime sleep is often shorter and lighter because of daylight, noise and family activity.
Shift work disorder raises the risk of accidents, errors and drowsy driving home after shifts. Planned naps, careful light timing and protected sleep can help, and medicines are available when sleepiness persists.
A 2021 meta-analysis of 29 studies estimated that about 26.5% of shift workers meet criteria for shift work disorder, though definitions varied widely between studies.
Common symptoms
- Trouble falling or staying asleep after shifts
- Excessive sleepiness during work
- Short, unrefreshing sleep
- Difficulty concentrating and more errors
- Irritability or low mood
- Feeling drowsy when driving home
Causes and risk factors
- Night shifts and early morning starts
- Rapidly rotating schedules, especially rotating backward
- Long shifts and overtime
- Daylight exposure on the way home after a night shift
- Noisy or bright sleep environment during the day
- Being a natural early riser (morning type) working nights
How it is diagnosed
Diagnosis is based on insomnia or excessive sleepiness linked to a work schedule that overlaps with usual sleep time, lasting at least three months. A sleep diary and actigraphy over at least 14 days, covering work and free days, help confirm the pattern. Clinicians also look for other sleep disorders such as sleep apnea.
Treatment options
Planned naps
A nap before a night shift, or a short break nap during it where permitted, improves alertness.
Bright light during the shift
Exposure to bright light during the night shift can help the body clock adapt.
Light blocking after the shift
Dark glasses on the way home and a blacked-out bedroom support daytime sleep.
Melatonin before daytime sleep
May help some people sleep after night shifts.
Wake-promoting medication
Modafinil and armodafinil are FDA-approved to improve sleepiness in shift work disorder.
Schedule changes
Forward-rotating shifts and avoiding quick turnarounds can reduce symptoms.
What you can do yourself
- Make your bedroom dark, quiet and cool, using blackout blinds and earplugs
- Wear sunglasses on the way home after night shifts
- Keep a consistent sleep time on work days
- Use caffeine early in the shift and avoid it near the end
- Ask family to protect your sleep time
- Pull over and rest if drowsy when driving
When to see a doctor
- You fall asleep at work or nearly crash while driving
- You cannot sleep despite a good daytime routine
- Sleep problems persist on days off
- Mood, health or relationships are suffering
Frequently asked questions
What is the best sleep schedule for night shift?
Many night workers do best sleeping in one main block soon after getting home, sometimes with a nap before the next shift. Consistency matters, and a dark, quiet room is essential.
Should I take melatonin after a night shift?
Melatonin taken before daytime sleep helps some shift workers. Ask a clinician about timing, since melatonin taken at the wrong time can shift your clock in the wrong direction.
Is it dangerous to drive home after a night shift?
Drowsy driving after night shifts is a real risk. Consider a short nap before leaving, carpooling or public transport, and pull over if you feel sleepy.
Can I adapt fully to night shifts?
Most people only partially adapt, especially if they switch back to a daytime schedule on days off. Strategies like light timing and planned sleep improve tolerance.
Sources
This page is general information, not a diagnosis or medical advice. Read our medical disclaimer.