It might surprise you, but there may be a "battle of the sexes" going on each night right in your bedroom. Aside from commonly heard complaints like one partner stealing all the covers, or the other partner snoring, there are a wide range of statistically significant ways that men and women differ when it comes to sleep -- and these differences could negatively affect your sex life.

Sleep Differences Between Men and Women

Insomnia, which is defined as difficulty falling asleep or staying asleep, is approximately twice as common in women than in men. This difference emerges around puberty, prompting researchers to speculate that the sleep differences between men and women are at least partially due to the effects of male versus female hormones. This increased prevalence of insomnia in women holds true across their lifespan, albeit at different rates. In midlife, women are 40 percent more likely than men to suffer from insomnia, while at age 65 this increases to a 70 percent higher likelihood.

Sleep disorders can also manifest differently in men versus women. For example, the sleep disorder narcolepsy often creates a different set of symptoms in women than it does in men. Experienced by only about one percent of the population, narcolepsy is characterized by severe daytime sleepiness, disturbed sleep-wake cycles, falling asleep suddenly at inappropriate times during the day and other symptoms. Compared to men, women show symptoms of narcolepsy at a younger age and are more likely to experience the daytime sleepiness symptom compared to other narcolepsy symptoms.

Another sleep disorder that presents differently in women than men is obstructive sleep apnea. This disorder is when there are multiple pauses in breathing during sleep, leading to sleep fragmentation, low oxygen levels during sleep, low sleep quality, daytime sleepiness, cognitive impairment and more. Men are more likely than women to snore as a result of sleep apnea, while women are more likely to experience fatigue, insomnia and depressed mood due to the decreased sleep quality. Experts believe that sleep apnea is under-diagnosed in women, due to their different set of symptoms.

Beyond sleep disorders, there are also innocuous differences between men and women's sleep. For example, men dream more than women. This is because the higher progesterone levels during a woman's second half of the menstrual cycle cause the body temperature to rise, reducing the duration of REM sleep (the sleep phase during which dreams occur).

The Reason Behind the Differences: The Circadian Rhythm

The disparity in sleep disorder frequency between men and women is due to a difference in their circadian rhythms. The circadian rhythm can be thought of as the daily biological clock, controlled by the brain. Scientists have identified many differences between the male and the female circadian cycle. For example, women are more likely to be early birds while men are more likely to be night owls.

Sleep Differences Between Men and Women Could Affect Your Sex LifeOne groundbreaking study, published by the National Academy of Sciences in 2016, explored these circadian differences in great depth. The researchers found that women have lower alertness levels at night and in the early morning compared to men, but they also have higher alertness levels in the late afternoon than men. On average, women start to get tired about two hours earlier in the evening than men do.

However, in general the average woman still goes to bed around the same time as the average man. This means that women initiate sleep during a later circadian phase than men. The authors of this study believe that this circadian mis-match may be a contributing factor to the increased prevalence of sleep disorders in women. Women have more trouble staying asleep at night, and are more likely to wake up earlier than intended. Women also have a lower tolerance for shift work, plus an increased risk of work-related injuries while doing shift work, suggesting an increased susceptibility to fatigue and cognitive impairment from sleep deprivation than men.

How Does Sleep Affect My Sex Life?

Understanding the circadian rhythm, as well as how it relates to your specific gender, is important for optimizing your sleep. Sleep hygiene tips for increasing sleep quality are based on maintaining a healthy circadian rhythm. Good sleep is important for many different aspects of your health, while reversely, sleep deprivation has negative health effects, including decreased memory, lower stress tolerance, trouble concentrating, lowered mood, high blood pressure and an increased risk of heart attack.

Surprisingly, how well you sleep also has effects on your sexual health. This is because many of the things that sleep influences, such as mood, stress levels, and hormones, are things that influence your libido. The effects of sleep on your sex drive have been observed by many studies. One study in particular, published in the Journal of Sexual Medicine, found that for women, getting one more hour of sleep every night increases the libido by 14 percent.

Sleep is imperative for men's libidos as well. One eye-opening study on this topic was conducted at the University of Chicago Medical Center, and published in the Journal of the American Medical Association. This study found that men who slept for less than five hours every night had significantly lower testosterone levels than men who got a full night's sleep—a loss of testosterone equivalent to aging 15 years. Testosterone is the most important hormone for men's sex drives; however, it also affects muscle mass, bone density, energy and mental health.

For both men and women, getting enough sleep and aligning your lifestyle with your natural circadian rhythm will optimize your health, including your sexual health and overall sexual satisfaction.