It doesn’t matter if I sleep a full eight hours or struggle through a meagre five ― I’m always groggy, confused and sleepy first thing in the morning.
That’s not just because most women need more sleep than men, it seems. According to The Sleep Foundation, I might be dealing with sleep inertia.
The phenomenon, which can make you disoriented, drowsy and uncoordinated, has no known cause.
But experts think it could happen when a person is woken during non-REM sleep, due to changes in blood flow, or because of higher levels of adenosine.
Some speculate it helps to protect sleep that may have been interrupted. But how does it present, and what can you do to get rid of it?
Sleep inertia doesn’t last long
Researchers say the experience usually only lasts between a quarter of an hour to an hour.
While that doesn’t sound long, scientists say the period of impairment is “of concern to workers who are on-call, or nap during work hours, and need to perform safety-critical tasks soon after waking”.
Indeed the Centre For Disease Control (CDC) has looked into how the condition affects nurses, saying it can result in “slower reaction time, poorer short-term memory, and slower speed of thinking, reasoning, remembering, and learning”.
The CDC says it’s likely to last longer if you’re sleep-deprived and adds that longer periods of sleep inertia were seen among people – such as shift workers – who took hour-long naps during early morning hours (between 4 and 5 am).
They stressed the importance of allowing sleep inertia to pass before doing any critical work.
How can I get rid of it?
Some studies have found that caffeine is a good way to get rid of sleep inertia.
Caffeine blocks the parts of your body that receive adenosine, a chemical that makes you sleepy and can lead you to struggle to wake up.
That has led some researchers to back the higher adenosine levels = sleep inertia theory we mentioned earlier.
The CDC points out that caffeine takes about half an hour to get to work and adds some people might benefit from drinking it before a nap.
Bright lights and washing your face might also make you feel alert more quickly, the CDC adds.
