The short answer
A short nap, twenty minutes and before mid-afternoon, helps. A long one, or a late one, takes the edge off the following night.
- Twenty minutes or less avoids dropping into deep sleep, which is what causes the groggy, worse-than-before feeling.
- Before about three in the afternoon, so it does not eat into the night's sleep pressure.
- Set an alarm, because the difference between twenty minutes and ninety is the whole point.
- If you are not sleeping at night, skip naps entirely until the nights are better.
What will ruin it
Persistent daytime sleepiness despite adequate sleep at night is worth investigating. Sleep apnoea is common, treatable and frequently undiagnosed, particularly where there is loud snoring.
Why it works
Sleep pressure builds through the day and a nap discharges some of it. A short nap takes the edge off without spending the reserve you need for the night.
This is general information, not medical advice, and it does not replace a GP, a pharmacist or NHS 111. Call 999 in an emergency. Full disclaimer.