Is microsleep good for you?
Microsleep is a brief, involuntary episode of sleep when you are trying to stay awake. It is a warning sign of dangerous sleepiness, especially while driving or using equipment; it is not a planned power nap or a reliable way to recover from fatigue.
If you feel drowsy while driving, stop in a safe place. Do not continue until you are alert and have a safe plan for the rest of the trip.
What is microsleep?
The CDC’s NIOSH guidance describes microsleeps as brief sleep episodes lasting from a fraction of a second up to about 30 seconds. A person may not realize an episode occurred. Losing attention for even a few seconds can be dangerous when driving.
A planned nap is deliberately taken in a safe place. Microsleep is involuntary and can happen during a task when a person intends to stay awake.
Warning signs of drowsiness
Heavy eyelids, frequent yawning, difficulty focusing, missing turns, drifting in a lane or not remembering the last stretch of road can signal dangerous fatigue. These signs do not prove that a microsleep occurred, and an episode can happen without an obvious warning.
If you notice them while driving or doing safety-sensitive work, stop the activity and move to a safe location. Opening a window or turning up music is not a reliable way to remain awake.
What to do if you are sleepy while driving
Pull over somewhere safe, stop driving and arrange adequate rest or an alternative driver or ride. CDC guidance discusses caffeine and a short nap as temporary countermeasures, but warns that they may not be enough when severely sleep deprived. If you remain sleepy, do not resume driving.
Plan ahead for long trips, avoid driving during your normal sleep period when possible, and schedule breaks. No technique reliably lets a severely sleep-deprived person force themselves to stay awake.
What can contribute?
Not getting enough sleep, long or irregular work hours, medications, alcohol and some sleep or medical disorders can contribute to sleepiness. Monotonous tasks can make it harder to stay alert. A clinician can help assess the underlying cause; microsleep alone does not diagnose sleep apnea or insomnia.
When to seek help
Discuss recurrent or unexplained daytime sleepiness with a healthcare professional, especially if you fall asleep unintentionally or have loud snoring, pauses in breathing during sleep or difficulty functioning during the day. Bring information about your sleep schedule, medications and when episodes happen.
Until the cause is addressed, avoid driving or other safety-sensitive activities whenever you feel sleepy.
Frequently asked questions
Is microsleep the same as a nap?
No. A nap is planned; microsleep is an involuntary episode when someone is trying to stay awake.
How long does it last?
NIOSH describes episodes from a fraction of a second up to about 30 seconds.
Can caffeine make a sleepy driver safe?
It may temporarily increase alertness, but it is not reliable when someone is severely sleep deprived. Stop and arrange safe rest or transportation.
Does microsleep mean I have sleep apnea?
No. Sleepiness has several possible causes and warrants evaluation when recurrent.