Is your period keeping you up at night? From headaches, depression and anxiety, to cramps, digestive issues and breast tenderness, the rollercoaster ride of our fluctuating hormones doesn't just switch off when we go to bed. According to research by the US National Sleep Foundation, 30 per cent of women experience disturbed sleep during their periods, while 23 per cent report sleep issues during the week before menstruation.
"I experience a multitude of symptoms about two weeks before my period," Kirsty tells me. "As far as sleep goes, I initially go through insomnia, then in the week before I feel the need for ten hours a night – which never happens – and still find it difficult to function."
For Anna, it's all about one particular night: "About five days before my period starts, I can't sleep for love nor money. I think my body temperature rises and makes it impossible to sleep," she says. "Usually around 2am I realise it's 'that night' and I just give in and watch/read/scroll."
These kinds of disturbances could be a result of changing levels of the hormones oestrogen and progesterone. They rise during the 'luteal' or 'secretory' phase of your cycle, which lasts for roughly two weeks between ovulation and menstruation. Your core body temperature rises slightly after ovulation, and you may experience premenstrual symptoms during this phase. Oestrogen and progesterone levels then fall again before your period starts.
Danielle uses hormonal contraception, so doesn't experience the same hormonal fluctuations throughout the month and has a withdrawal bleed during her pill-free week, rather than a menstrual period. Despite this, she tells me, "I definitely sleep worse during that time of the month" – largely because of anxiety about leaving her tampon in for too long.
"It sounds stupid, but I get worried about how long I can wear a tampon for, so I don't like to go to sleep until as late as I can, and also get up as early as I can," she explains. "I also sometimes wake up in pain during the night. I get backache and headaches while I'm on and the week before, so I feel achy and drained, but then lie there awake."
Like all things hormonal, the relationship between sleep and the menstrual cycle is a complex one, affecting different people in different ways. And, like many areas of women's health, we simply don't yet know enough about the links between hormones and sleep. "There are limited high-quality studies that look at sleep and menstrual cycle," says Dr Jacqueline Maybin, Consultant Gynaecologist at the University of Edinburgh and a spokesperson for medical research charity Wellbeing of Women.
"Some studies suggest that people who menstruate have poorer sleep quality during the 'late secretory phase' (i.e. in the few days before bleeding starts). However, when other factors like stress and social support are considered in the analysis, there appears to be no clinically significant alteration in sleep across the cycle," she explains.
It means I have to plan my social life around my physical symptoms and tiredness. Sometimes this means not leaving the house for anything other than work during my period as I'm exhausted.
Where there is more robust evidence, Dr Maybin adds, is around the impact of dysmenorrhoea (that's period pain to you and me) and other menstrual symptoms and conditions – including endometriosis, polycystic ovary syndrome (PCOS) and premenstrual syndrome (PMS), or its more severe form, premenstrual dysphoric disorder (PMDD).
"People who experience premenstrual and menstrual symptoms may report disrupted sleep. This can be from pain – in the form of cramps or headaches – or from increased fatigue and insomnia," explains Nicole Telfer, Science Content Producer at Clue.
"People who have premenstrual mood disorders are more likely to experience sleep disturbances like insomnia, hypersomnia, fatigue and even disturbing dreams during the luteal phase," she adds.
"My menstrual cycle affects my sleep greatly," says Lizzy, who suffers from PMDD. "It causes me to have bouts of insomnia after ovulation. I will be able to fall asleep easily, but staying asleep is almost impossible. I wake in the middle of the night, for at least 3-4 hours, almost always around 2 or 3am, and have very high anxiety and obsessive thoughts."
Inevitably, Lizzy adds, this has a terrible impact on her during the daytime too. "Not being able to sleep properly causes me to have anxiety and brain fog during the day, so normal everyday situations become stressful and exhausting," she explains.
Polycystic ovary syndrome (PCOS) is also associated with sleep problems, and may increase the risk of sleep disordered breathing issues, such as sleep apnoea – where your breathing stops and starts as you sleep – or snoring. Meanwhile, physical symptoms such as pain, bloating, and heavy bleeding (which can be a sign of conditions like endometriosis or fibroids) can all disrupt sleep if they're severe enough to keep you awake, wake you up, or require you to change your menstrual products in the middle of the night.
Jenn lives with endometriosis, and tells me: "Three days before my period I know that I won't be able to sleep. It takes me a long time to go to sleep as my body feels bloated and incredibly hot, but when I do, I wake up at around 4am with cold sweats and can rarely get back to sleep."
This goes on for three nights each month, Jenn explains, and also happens to a lesser extent around ovulation. "It means I have to plan my social life around my physical symptoms and tiredness. Sometimes this means not leaving the house for anything other than work during my period as I'm exhausted," she says.
Beyond the month-to-month, other stages in our reproductive lives can also have an impact on sleep quality – from the hormonal and physical changes involved in pregnancy and the postnatal period (not to mention the practical reality of having a screaming bundle of joy in close proximity to your bed during the latter), to the declining oestrogen levels you'll encounter before and after the menopause.
For some women, this drop in oestrogen can cause symptoms including hot flushes and night sweats. 52-year-old Coleen, who's in the midst of perimenopause, says these have had a profound impact on her sleep. "[At first] I was waking up drenched in sweat and needing to change at approximately 4.30am every day," she explains.
"Those have now been replaced by hot flushes, which occur all throughout the day and night. Now the night sweats aren't waking me up, but I have to take my bed sheets and covers off and on throughout the night, depending on whether I'm too hot or have the chills, so it's a more fitful sleep," Coleen adds.
So, what can you do about hormone-related sleep disturbances? Currently, not a lot beyond the usual common sense advice of eating well, exercising and spending time outside regularly, avoiding caffeine later in the day, and limiting screen time before bed.
Pain relief can help to alleviate sleep-disturbing cramps, but it's important to get more serious menstrual problems checked out by a healthcare professional for proper, personalised treatment. This might include suppressing period symptoms with hormonal contraceptives, managing menopausal symptoms with HRT, or exploring alternative options.