You likely already know that getting plenty of sleep at night is in your best interest, but you might not have ever given much thought to the effects that sleeping during the day can have on you, particularly if you don't typically need to spend much time sleeping during the day. Sleep is exceedingly important for your short and long-term physical and mental health and wellbeing, so if you do sleep during the day (either to nap or because you're up at night), you need to know about the surprising effects sleeping during the day has on your health long-term.
People who work at night, of course, need to sleep during the day. For those who don't work at night, you still might find yourself occasionally napping during daylight hours, but you're probably better off still getting your normal recommended amount of sleep at night to minimize potentially-negative effects. "We are naturally programmed to sleep at night — light is a major trigger that sends the chemical signals to wake — so daytime sleeping is really hard and it is difficult to get the full seven and a half hours of good, restful sleep," Dr. Anthony Warren, PhD, a sleep expert and CEO of BreatheSimple, tells Romper by email. If you have to sleep during the day for any reason (maybe you were up all night with the baby, for instance), if you can time it right, you might also be slightly better off.
"As far as the timing of the day for the nap, if you are on a normal sleep pattern, our bodies tend to have a natural drop in temperature between 2pm and 4 pm each day," Bill Fish, certified sleep science coach and co-founder of Tuck, tells Romper in an email exchange. "When this takes place, the body begins to produce melatonin, which can cause drowsiness. If you do try to nap, keep it in that window, always avoid napping less than three hours before you go to bed for the night otherwise you have the potential of experiencing prolonged sleep latency."
Sleeping during the day and working at night regularly can really take a toll on your health and your general wellbeing. "The fact is that our natural circadian rhythm requires that we sleep at night when the sun is down," Chris Brantner, a certified sleep science coach and founder of SleepZoo.com, tells Romper in an email exchange. "You simply can't effectively reprogram yourself to be nocturnal. Not only that, our entire world is built around a nighttime sleep cycle. So even if it was good for you to sleep all day, the world around us makes it difficult."
If you're sleeping during the day regularly, these effects are things about which you should definitely be aware.
1. You Have Increased Inflammation
Too much inflammation isn't a good thing for your health and not getting enough sleep consistently, which can be a problem if you have to sleep during the day, can make inflammation worse, Brantner says. "While power naps may seem to mitigate the temporary effects of sleep deprivation, they aren't a substitute for the eight hours you need at night," he adds.
2. Your Brain Might Actually Change
A 2014 study published in the Journal of Neuroscience found that chronically losing out on sleep, as many who are up at night do, might even change your brain. This study was done in mice, so more research is likely needed, but it's still important to keep in mind. Not only that, but another 2014 study published in the journal Sleep found that some veterans of the Gulf War who didn't get enough sleep had a decreased volume of brain tissue.
3. Your Hormone Levels Will Change
Getting enough sleep each night is also tied to your hormone levels and production. If you don't sleep enough, eating a healthy diet might be especially important. "They have to more careful in their dietary habits to reduce the hormonal changes (increased cortisol) that comes disruption of circadian rhythms," Dr. Barry Sears, the creator of the Zone Diet, tells Romper by email. "Those hormonal changes result in insulin resistance that causes weight gain and a greater likelihood of diabetes and heart."
4. You End Up Dealing With Sleep Fragmentation
Sleep fragmentation is basically what happens when you get some of your sleep at night and some during the day. While not everyone who sleeps during the day would have to deal with sleep fragmentation, it can definitely be an issue for new parents and others. Essentially, you have naps that interfere with your nighttime sleep, which you don't want to happen.
"When it does, we call this sleep fragmentation — where people sleep poorly at night, and need to nap long periods of time by day — which then in turn, impacts night time sleep, and so the cycle goes," Dr. Alex Dimitriu, MD, a psychiatrist and sleep medicine specialist, tells Romper via email. "Short naps are OK, as long as they do not lead to insomnia and poor sleep at night, and often, napping less than 30 minutes keeps things under control."
5. You Have A Greater Risk Of Some Serious Conditions
Because people who sleep during the day often aren't getting an adequate amount of sleep in general (even if they are sleeping some at night as well), they might also be more likely to develop certain serious conditions.
"This inadequate amount of sleep has been shown to increase inflammation and raise the risk of heart disease, Alzheimer's, cancer, all-cause mortality, and a host of other serious health issues," Brantner says.
6. Napping Can Help You Be At Your Best During The Day
There are some benefits to napping, however, as well. "Napping, as long as it's less than 30 minutes, can be beneficial in boosting mood, creativity, as well as energy levels," Dimitriu says. "There is a good amount of research that shows we can solve problems in our sleep, and even help consolidate new memories to more permanent storage."
"I often counsel my patients, whether they are working night shifts or day shifts, that a short 30 minute nap is often better than a cup of coffee," he adds. "Though some evidence exists that both may be the killer combo for productivity — some of my clients will actually drink a coffee and immediately nap, and wake feeling doubly refreshed and productive. Again, better not to nap within 6 hours of true bedtime. Besides napping, which can help everyone, shift work has been shown to have negative long-term effects on health, mood, and wellbeing."
So there can, in fact, be benefits to napping, as long as you're making sure to take everything into consideration.
7. You Might Experienced Lower Libido Or Lower Sperm Count
Additionally, again, because many people who sleep during the day for whatever reason aren't getting enough sleep in general, it's important to know that sleep deprivation and poor sleep quality can also be tied to lower libido or lower sperm count, as Warren says. And that's not great either.
Luckily, there are some things that you can do to help yourself make the most of your daytime sleep. "Setting up your bedroom as a dark quiet place is a must," Fish says. "Invest in some blackout shades to at least trick your body to give the feeling that it is night. Another solution is to purchase a white noise machine. There are simply more noises throughout the day than what you would expect at night, so a simple $40 purchase can muffle many of the noises that would tend to wake you while sleeping during the day."
Whether you sleep during the day because you didn't sleep well last night or because you absolutely have to on a regular basis, it's useful to know how it might be affecting you both now and in the future.