This condition is not often talked about, but chances are you’ve experienced it yourself
What is microsleep?
Microsleep refers to very small periods of sleep that can be measured in seconds rather than minutes or hours. We may colloquially refer to it as ‘nodding off’, even keeping our eyes open while we do it, but chances are you or someone you know has experienced it.
Microsleep is generally defined as sleep that lasts for 15 seconds or less, and is known to occur in both humans and animals. Researchers are now able to detect episodes of microsleep by looking at brain activity, as studies have found that brain waves noticeably slow down during microsleep. The Sleep Foundation reports that the brain also responds to sound differently during microsleep than while fully awake or asleep, responding to sound but failing to differentiate between pitches.
What are the symptoms of microsleep?
Microsleep can occur with your eyes closed or open, but it is almost always paired with a nodding head. However, while you may think you would know when you’ve experienced microsleep, it is not always obvious. Not everyone who microsleeps knows it has taken place.
During microsleep, our responses to visual or audio cues are slowed, and we tend to move our eyes more slowly in the moments leading up to microsleep too. Blinking and changes in heart rate have both been commonly accepted as signs of microsleep occurring.
What are the risks of microsleep?
While it’s unclear whether microsleep itself causes any harm, the main risk of microsleep is that it occurs at a time when your full concentration is required, such as while driving or operating heavy machinery. In one study published in Frontiers in Neuroscience in 2020, researchers found that microsleep was associated with a decrease in driving performance.
What’s more, some researchers are exploring whether microsleep could be a sign of a wider sleep disorder. One study published in Sleep Medicine found that identifying microsleep during a multiple sleep latency test (MSLT) can help professionals more accurate diagnoses excessive daytime sleepiness.
What causes microsleep?
Sleepiness and sleep deprivation are the most common causes of microsleep, which is why the phenomenon is more likely to occur in shift workers and those who already experience sleep disorders like insomnia and obstructive sleep apnoea.
A single bad night’s sleep can increase your risk of microsleep, and the more sleep deprivation you suffer, the more likely you are to nod off during the day.
Can microsleep be treated?
There is currently no universal treatment recommended for microsleep, but as it is related to sleep deprivation and sleepiness, the most promising cure is to prioritise good sleep quality and quantity.
The National Sleep Foundation recommends getting between 7 and 9 hours of sleep a night for adults. Setting yourself a sleep schedule that you can stick to – waking up and going to bed at the same time every night – can help ensure both your brain and body are rested and energised during the day. You should also keep your bedroom cool and dark, avoid screens in the run up to bedtime, and engage in some relaxing activities in the hour before sleep, such as stretching, reading or meditation.