Meir Kryger, MD, a sleep disorder expert at Yale Medicine, says that being tired during the day and having energy during the night is usually caused by circadian rhythm abnormalities, explaining that it means a person’s body clock slows and they have a burst of energy at night. He says people often. There are three main causes of circadian rhythm sleep disorders: genetics, the environment, and a medical condition. Advanced sleep disorder and late sleep disorder have been associated with specific forms of certain genes in some individuals.

Not getting enough sleep, sometimes by choice, is the most common cause of excessive sleepiness. Working at night and sleeping during the day is another. Other causes include drug, alcohol, or cigarette use, lack of physical activity, obesity, and the use of certain medications. Almost everyone has days when they are sleepy.

But for some people, excessive sleepiness actually gets in the way of daily work, childcare, and even leisure activities. This is known as hypersomnia, recurrent sleepiness that makes people want to take naps repeatedly, even at work. This cycle interacts with the homeostatic impulse of sleep to produce a period of wakefulness during the day and continuous sleep during the night. Taking a nap in the late afternoon can worsen daytime sleepiness if it can interfere with nighttime sleep.

But randomly setting an ideal bedtime can lead to more frustration if you suffer from insomnia and already have trouble falling asleep, says Barry Krakow, MD, medical director of Maimonides Sleep Arts and Sciences Ltd. Because a good night’s rest is essential for the body’s recovery and repair, those who don’t get enough sleep on a regular basis have a higher risk of suffering from certain disorders, such as high blood pressure, cardiovascular disease, obesity, diabetes and depression. But you may not know that you have sleep apnea unless your bedmate tells you about the fuss you are creating. A bedtime relaxation routine can help you separate yourself from the day, especially from activities that are overstimulating or stressful, making it difficult to sleep.

Another remedy may be to improve sleep hygiene by going to bed and getting up at the same time every day, avoiding caffeine in the afternoon and at night, and maintaining a relaxing environment in the bedroom. Sometimes a combination of medication and behavioral therapy is needed to eliminate daytime sleepiness, but it can be done. Get into bed when you’re sleepy: droopy eyes, sleepy, you feel like you’re nodding. Sleep apnea occurs when the upper airways collapse for at least 10 seconds during sleep, and it does so up to hundreds of times each night.

Avelino Verceles, MD, Assistant Professor and Director, Sleep Medicine Fellowship, University of Maryland School of Medicine, Baltimore. Depression or a sleep disorder, such as restless legs syndrome, sleep apnea, or narcolepsy, are common causes of problematic sleepiness. Even losing just a few nights of sleep, or not getting enough sleep without interruption, can cause your pace to slow down and worsen your mood. A person’s environment or situation can cause temporary circadian-related sleep disorders, such as jet lag.

References
Circadian rhythm sleep disorders | You and Your Hormones from the Society for Endocrinology
https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/sleep-hypersomnia
Sleep disorders: MedlinePlus Medical Encyclopedia