According to a poll by the National Sleep Foundation, 67% of women who menstruate have poor sleep patterns (toss and turn) for two or three days during every menstrual cycle. This poll was conducted by Dr Kathryn Lee, a sleep researcher at the University of California, San Francisco.
Does sleep quality change across the menstrual cycle in women?
Up to 70% of women say that their sleep changes just before their period.
The most common time for this is 3 to 6 days before having the period. According to Dr Lee “those women who have regular cycles and who monitor their sleep frequently find that they also have insomnia a day or two before menstruation begins”. “It kind of gets lost in the tossing and turning at the beginning of menstruation unless you keep a sleep log,” she adds. “Then it jumps right out.” Premenstrual insomnia, as doctors call it, seems to be associated with a rapid drop in the hormone progesterone. Premenstrual insomnia not only affects your ability to sleep, it also seems to affect the quality of your sleep.
Above is an overview of the stages of sleep. The time is obviously not fixed but on average we normally start REM sleep (Stage 5) around 90 minutes after we fall asleep. However ovulation occurs progesterone makes womens temperature go up, REM sleep occurs earlier in the sleep cycle, within 60 minutes. As a result, women during menstruation women often skip over, or significantly reduce the deep sleep stage (Delta) that usually occurs right before REM sleep.
This has implications as the Delta sleep stage is where your body repair mechanisms come into play. Technically speaking cells increase their production of proteins that repair damage from stress and ultraviolent radiation. A non technical way of explaining it is, the delta sleep stage is when the immune system powers up. In children this is when the growth hormone is secreted. In adults this is when the body heals.
Progesterone is soporific (or sleep inducing). If (just before menstruation) your progesterone levels drop is gradual your sleep patterns will be only slightly impacted. However if they drop dramatically you are very likely to wake up in the middle of the night.
There is also research from Dr Lee which shows that women with Premenstrual Syndrome (PMS) had no deep sleep at all…..all month long! Imagine the impact that has on the immune system cumulatively over time. Their sleep patterns looked like that of jet-lagged and depressed people.