You’re exhausted and driving home late. It becomes increasingly hard to focus on the road, and you start blinking more slowly. Should you press on or pull over?
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“Short bursts of sleep, or microsleep, while driving can be dangerous,” says sleep expert Samuel Gurevich, MD. “It’s important to recognize it’s happening and the situations that cause it and to take it seriously. Sleepiness causes a significant number of car and industrial accidents. Microsleep can have big impacts on you and those around you.”
Dr. Gurevich explains microsleep and shares some helpful tips for protecting yourself and others.
What is microsleep?
Microsleep involves very brief periods of sleep that last up to 30 seconds — and you don’t always notice them happening. “It can occur while you’re on your couch watching TV or reading a book,” notes Dr. Gurevich. “But it’s dangerous when it happens when you’re behind the wheel of a tractor-trailer or at a switch in a nuclear power plant. There are unfortunately a lot of industrial accidents where sleepiness is the culprit.”
Microsleep vs. micronap
While microsleep is a clear sign you need more rest, a micronap is something you do to get it. “When people say micronapping, they’re referring to a type of regular power nap where they sleep 20 to 30 minutes at the same time each day to replenish themselves,” explains Dr. Gurevich. “They’ve trained their bodies to expect this time, and the habit works well for some. It puts a little more fuel in their tank.”
But you can experience the opposite if your micronap turns macro. “If you sleep too long or late in the day, it can keep you awake at night.”
What causes microsleep?
The most common cause of microsleep is sleep deprivation. “When we borrow time from sleep to socialize, work or study, our brains remain tired and seek that missed sleep. The longer it’s been since you were last asleep, the sleepier you get,” says Dr. Gurevich. “Eventually, the brain tries to proactively put you to sleep, and often, it can happen in dangerous situations. Driving is one of the most common ones.”
But lack of rest isn’t the only thing that makes your body crave sleep. Other things that can trigger episodes of microsleep include:
- Drinking alcohol.
- Taking medications with sedative or hypnotic qualities, such as antihistamines or sleeping pills.
- Having a medical condition that affects your sleep, such as sleep apnea or insomnia.
- Working a night shift.
Warning signs that you’re having microsleep episodes depend on the situation. If you experience microsleep while driving, for example, you may not remember seeing parts of the road or the last four or five seconds behind the wheel, says Dr. Gurevich. “Having to fight to stay awake by opening the window or playing music is another strong indicator that your brain is trying to transition to sleep.”
In other situations, microsleep symptoms may include:
- Blinking slowly or constantly.
- Having trouble understanding information.
- Jolting awake with sudden body movements.
- Yawning excessively.
“A lot of patients also mention how they think they’re getting sleepier because they’re older. But we need less sleep as we age. So an older adult should feel alert even with fewer hours of sleep. They shouldn’t feel sleepy all the time,” explains Dr. Gurevich.
“Or some people blame excessive tiredness on their busy schedule. And while these can be factors, I urge people to use previous energy levels as a frame of reference. If you feel more tired and less energetic than you used to, check in with your healthcare provider.”
How to prevent microsleep
Dr. Gurevich says the first step to preventing microsleep is recognizing when you’re tired and not trying to push through it. “The consequences can be so severe. You’re potentially putting people’s safety at risk — including your own. If you’re tired while driving, find a safe place to pull over to take a short nap to refresh yourself,” he advises.
Even better, he says, “Don’t take a long drive if you’re sleep deprived. Rearrange your schedule and catch up on your sleep first. So many people get hurt or worse because of this phenomenon.”
Dr. Gurevich also recommends:
- Don’t rely on stimulants like caffeine to keep you awake.
- Avoid medications and substances that make you drowsy, including alcohol, before periods where you must be alert.
If you experience microsleep, your doctor will:
- Thoroughly review any medications you’re taking to see if they’re causing microsleep.
- See if you’re exhibiting signs of other medical conditions that can cause sleepiness.
Dr. Gurevich says a lot of common, treatable conditions can lead to microsleep, including:
- Heart failure.
- Kidney disease.
- Liver disease.
- Low thyroid levels.
- Parkinson’s disease.
- Sleep disorders, such as sleep apnea.
Why sleep is so important
Beyond causing microsleep, lack of sleep is bad for your health and prevents you from functioning at your best.
“In the short-term, being drowsy can affect your focus and attention, short-term memory and other executive processes. In the long-term, insufficient rest can increase your risk for mood disorders such as depression and anxiety, cardiovascular disease and stroke,” Dr. Gurevich says.
“Getting enough good quality sleep — typically about 8 hours or whatever you need as an individual to feel well the next day — is really important for your total health.”