By now, we tend to accept the importance of sleep for our mental and physical health. 

We practice sleep hygiene – avoiding caffeine in the afternoon, dodging blue light in the evenings and banishing our phones into another room overnight. These things work for many of us, but not all factors affecting our sleep are within our control.

Over two thirds (67%) of UK adults have disturbed sleep, rising to 74% among women, many of whom have monthly periods. 

The menstrual cycle affects our ability to drop off in many ways, but rarely is this mentioned in relation to the sleep issues that plague huge swathes of the population.

30% of women experience disturbed sleep during their periods, while 23% report sleep issues during the week before menstruation, according to research by the US National Sleep Foundation.

From cramps, bloating, digestive issues, nausea and breast tenderness, to headaches, depression and anxiety, the reasons your period may affect your sleep are varied and many.

Like many areas of women’s health, a lot remains unknown about how the menstrual cycle affects sleep, due to a dearth of high quality studies.

But there is evidence into how dysmenorrhoea and other menstrual symptoms and conditions affect the quality of our shuteye, such as polycystic ovary syndrome (PCOS), endometriosis, premenstrual syndrome (PMS) and its more severe iteration premenstrual dysphoric disorder (PMDD). Here’s what we know about how periods affect sleep.

Hormonal changes during the menstrual cycle

Our hormone levels fluctuate throughout our cycle, which can wreak havoc on our sleep. Oestrogen and progesterone levels are low during our period and for the rest of the follicular phase (before the egg is released), which lasts about 14 days, during which time it may be harder to fall asleep. 

After ovulation, on around day 14, oestrogen and progesterone rise and your body temperature increases by about half a degree, remaining elevated for a few days. We sleep better when our body temperature is low, so this can also cause disturbed sleep and premenstrual symptoms. Oestrogen and progesterone then drop before your period starts again – another hormonal shift that can disrupt sleep quality.

People who use hormonal contraception won’t have the same peaks and troughs in hormone levels throughout the month, so they may not experience the same symptoms.

Why can't I sleep the week before my period?

The days leading up to your period (the ‘late luteal’ phase of your cycle) are a prime time for poor quality sleep, despite the NHS advising seven to eight hours to deal with PMS symptoms.

Around 70% of women say their sleep changes just before their period, with the most common time being three to six days before it’s due, according to Australia’s Sleep Health Foundation.

Troubled sleep is some people’s only PMS symptom, while for others it’s accompanied by the usual symptoms we know and hate: cramps and bloating, tender breasts, headaches, and the rest.

PMS might mean it’s harder to get to, and stay, asleep, a reduced chance of rapid eye movement (REM) sleep (which helps the brain respond to stressful situations, among other benefits), and feeling sleepy during the day.

Can PMDD cause insomnia?

People with PMDD are particularly predisposed to sleep problems.

Women with PMDD typically report “insomnia, frequent awakenings, non-restorative sleep, unpleasant dreams or nightmares, and poor sleep quality associated with their symptoms; and daytime disturbances such as sleepiness, fatigue, decreased alertness, and an inability to concentrate during the during the premenstrual week and during the first few days of menstruation,” says one paper in the journal Sleep Medicine Research. 

Can PCOS cause sleep problems?

PCOS, which typically involves irregular or missed periods and affects a fifth of women in the UK, can also cause trouble sleeping and lead to insomnia and poor sleep.

The syndrome has been linked to sleep apnoea, characterised by chronic snoring and a person’s breathing stopping intermittently during sleep. Over a third (35%) of women with PCOS may experience sleep apnoea, according to a recent meta-analysis.

Sleep apnoea can cause disrupted sleep and can affect oxygen delivery to the body, along with sleepiness and attention problems during the day, says the PCOS Awareness Association.

Can endometriosis cause sleep problems?

The physical symptoms of endometriosis, where tissue similar to the womb lining starts to grow in other places, can also lead to poor quality shuteye, according to research. These include pain and discomfort, digestive issues, hot flashes, fatigue (feeling physically exhausted or tired but not sleepy), heavy bleeding and frequent urination.

“Between my ribs feeling like they are cracking, pressure on my bottom from my bowels, and sharp pains shooting in many directions in my stomach, I don’t get much shut-eye,” writes Kimberli Davino, who lives with the condition.

Tampon anxiety

Aside from the physical stress is the mental anxiety of dealing with period blood, which can also make it difficult to sleep. Worrying about leaving a tampon in for too long, or about bleeding all over the sheets, can lead people to sleep poorly or even purposely reduce the amount of time they spend in bed.

What to do if your period’s keeping you up at night

 Keeping a sleep diary for a few months to track whether and how your menstrual cycle impacts your sleep quality, can be helpful, suggests the US’ National Sleep Foundation.

“If you know what to expect, you can take steps to protect your sleep and wake up feeling refreshed even while on your period.” List your symptoms each day, alongside when your period starts and stops, to help you draw a line between your sleep issues and PMS. 

Self-knowledge is power and knowing when you’re most likely to experience symptoms will enable you to help yourself. That might mean getting extra sleep and rest in the run-up to your symptoms, avoiding caffeine and alcohol, staying active, heading outdoors and/or eating healthily.

“Keep in mind that your poor sleep (and mood) will get better once your ‘problem time’ is over. This may mean you have less frustration and anxiety about your sleep,” says Australia’s Sleep Health Foundation.

See a healthcare professional if your period is seriously blighting your sleep and quality of life, and showing your sleep diary will give them a better idea of your symptoms, too.