How your menstrual cycle affects your sleep

It can seem as though everything affects your sleep—whether it’s the obvious connection between sleep and food, or the more subtle ties between temperature and slumber.

Your period—and fluctuations in hormone levels that come with it—are no exception. While not everyone who menstruates will experience these changes, about 50% of people who have periods do, says Fiona Baker, the Human Sleep Research Program director at SRI (formerly the Stanford Research Institute). Here’s everything you need to know about menstruation and sleep.

How are the menstrual cycle and sleep connected?

In short, there’s one key variable that correlates to both menstrual cycle and sleep, and that’s hormones. Particularly, there’s fluctuation in one hormone that seems to worsen people with periods' sleep during their cycles: progesterone.

Both estrogen and progesterone drop prior to a person’s actual menstrual cycle, says Sara Nowakowski, an associate professor at Baylor College of Medicine who specializes in sleep. Progesterone helps the body maintain and prepare the uterus for pregnancy, according to Yale Medicine. The hormone isn’t solely involved in pregnancy, though—it also improves mood and sleep. When the body realizes there isn’t a pregnancy, hormone levels “dramatically decrease,” Nowakowski says.

“Estrogen and progesterone really drop during that phase right before [menstruation],” she says. “That's kind of the hormonal fluctuation that we think is happening in some people that are kind of more predisposed to sleep problems. It’s what we consider hyper arousal—your body or your mind being kind of over-aroused,” she says.

Hormonal flux isn't the only interplay between sleep and menstruation. From pain due to cramping to an increase in disturbances throughout the night, there are a few other changes that people with periods may experience at “that time of the month.”

Does your menstrual cycle harm your sleep?

In many cases, differences in sleep are noticeable in objective and subjective assessments—meaning they’re scientifically measurable and reported by study participants. For example, researchers who used electroencephalograms or EEGs—which measure brain waves—to assess people’s sleep throughout the menstrual cycle noticed an uptick in “sleep spindles” following ovulation, during the luteal phase (the second half of the full 28-day cycle), Baker says. These patterns are thought to “be important for preserving sleep continuity and are also linked with sleep-dependent memory,” she explains. Turns out the increase in spindles spells good news for memory.

“In experiments looking at sleep-dependent memory, women remember better following sleep in the luteal phase than they do following sleep during menses, and their better performance seems to be related in some way to those sleep spindles,” Baker says. Her team is currently investigating the connection.

In other recent research, Nowakowski and her student saw changes in objective measures as well as participants’ reports. In particular, her team noticed “increased wake time during the night and disrupted sleep,” she says. These closely connect to another of the researchers’ findings: A decrease in sleep efficiency, which is calculated as a percentage of the time that you spend in bed and asleep. In the subjects’ perimenstrual phase, just a couple days before the onset of their periods, sleep efficiency was decreased—meaning they spent less of the time they were in bed actually sleeping.

In addition to changes in hormones, people with periods may also experience an increase in overall pain, thanks to cramps. Unfortunately, pain and sleep have a “cyclical relationship,” Nowakowski says. “The worse someone experiences pain, the more likely it is that they’re going to report their sleep is disrupted.” But the real kicker is that “the tolerance for pain goes down with sleep deprivation,” Nowakowski says. So, if you’re experiencing cramping pain that disrupts your sleep, or just sleep disruptions from your period in general, you may find your tolerance for the pain from cramps drops in subsequent days.

Of course, cramps aren’t the only type of pain that people experience during their period. Some may notice increased breast tenderness, which can be another type of discomfort that might change your sleep, Nowakowski notes. In conjunction with the emotional changes that some women experience—such as feeling more angry or depressed—all this creates "the perfect storm,” Nowakowski says.

As if it weren’t already enough, people with periods may also notice an increase in daytime sleepiness, Baker says. This may be especially common for people who have premenstrual syndrome or PMS.

One other notable change occurs with the body’s temperature. Changes in progesterone levels can affect a person’s temperature peaks and troughs, Baker says. In the luteal phase “body temperature does not drop as much at night as it does in the first part of the menstrual cycle,” she says. Slumber and temperature are intimately related, as your core temperature drops in the hours preceding sleep.

What can you do if menstrual symptoms affect your sleep?

Your menstrual cycle shouldn’t totally decimate your sleep for a week or two every month. Changes can happen, but they generally shouldn’t be that severe. If, for example, you’re waking up in the middle of the night to change your pad or tampon, or empty your menstrual cup, it’s probably not normal. People who have had children or those who have experienced miscarriages may fill a pad more quickly. Even so, if you’re filling your menstrual product of choice overnight within a few hours, Nowkowski says it’s worth talking to your gynecologist.

Baker and Nowakowski say hot water bottles can provide some relief from cramping pains. The warm sensation doesn’t heat your uterus, according to University of Utah Health. However, the expert explains, “thermally stimulating the skin can distract other nerve pathways involving pain.” Though it’s important that you don’t make the water bottle too hot. If you’re not sure where to begin, check out this well-reviewed hot water bottle that comes with a cute fleece-like cover.

Nowakowski has also run across people who swear by weighted blankets to improve their period symptoms. Her patients who like the blankets say they’re great for managing increases in stress or anxiety. Nowakowski also thinks the pressure could be helpful with discomfort that comes with periods.

Though circadian rhythm itself doesn't appear to change in accordance with the menstrual cycle, it's still important for sleep, Baker says. Things like exposing yourself to light in the morning, minimizing external light sources—cough cough, screens—in the evening, and maintaining a regular schedule are essential for everyone, she says.

What else is there to know about your period and sleep?

Research on the exact nature of interplay between periods and menstrual cycles is still growing, Baker says. “[This subject] doesn’t always get the attention it deserves in the general arena, although as a research topic, there has been a steady increase in research, which is a great thing,” Baker says.

Changes for people with uteruses don’t end with menstruation—in fact, the onset of menopause can lead to even more dramatic shifts in sleep patterns.

The best advice we can offer is to create a great nighttime routine—yes, that includes turning off the TV a few hours before bed—and sticking to a regular sleep schedule. Maintaining a pattern will help soften the blow of other changes that may come up as you menstruate.