We're tired of these injustices... and also just tired

There's a big gap between men and women when it comes to a lot of things, isn't there?

Pay? Orgasms? Tampon tax? You name it, women generally wind up with the shorter straw.

Turns out there's another gap you can add to that list: the sleep gap. Yep, research shows men generally get a better night's sleep than women. Who's surprised? Not us. According to the U.S. Department of Health and Human Services, women are more likely to have insomnia than men. A study by the National Centre for Health Statistics over there found that a whopping 20 percent of women suffer from chronic insomnia. Single mothers are the worst-suffering group – 25 percent have difficulty falling asleep and an alarming 50 percent claim they wake up feeling unrested. But what causes the sleep gap? There are a number of reasons why men tend to sleep better than women. Here's a look at what keeps us gals up at night.

Biology

Turns out that a lot of it can be blamed on menstruation. (I know, I know, it's always flippin' periods!) Apparently, folks who get periods will find their sleep disturbed throughout their cycles by hormonal changes (oh, hormones). During perimenopause, hot flashes and night sweats can also mess with sleep. Pregnancy is another sleep robber, as hormonal, physical, and emotional fluctuations can wreck shuteye. Add in leg cramps and the need to pee every 16 minutes because your bundle of joy is dancing on your bladder and you'll understand why you just can't get enough rest.

Children

Congratulations: that sleep-destroying bump has turned into a sleep-destroying baby, who will soon grow into a sleep-destroying toddler. And the thing is, even after the kids start sleeping through the night, mothers wake up easier and more often than dads do to listen and make sure the kids are asleep and okay. Perfect.

Stress, anxiety and depression

Women generally experience higher rates of all three conditions, which can either cause insomnia or insomnia can cause them. According to the experts, we're gluttons for taking on too much and running ourselves into the ground. Why? Societal expectations, mostly. A UN report claims women do almost three times more unpaid domestic labour than men. And with more and more women entering the workforce – and staying in it after having children – than previous decades, women are busier than ever. The task of trying to balance home and work responsibilities is often stressful enough to leave the mind restless. There's a fear of dropping the ball on one, the other or both, and given how women are also conditioned to feel shame or guilt more than men are, it's no wonder such fears keep them up at night.

Partners

The problem: the partner that catches so many more Zs than you seems determined to rub your nose in it by snoring like a chainsaw, keeping you awake for even longer. The solution: kicking them to the couch/spare room, divorce or murder, depending on the volume. Joking. On a serious note though, it's worth noting that married women reportedly experience higher levels of stress than single women, which may also contribute to the sleep gap. If your partner or relationship is causing you so much anxiety that you can't sleep, it's time to have a serious think about how you're feeling and how you can express it to them in hope of coming to a solution.

Bad sleep hygiene

Going to bed at the wrong time, too much light coming into your room, using devices before bed – it can all contribute to keeping us awake, ladies. Try to make the changes needed to make your bedroom a haven for sleep (and sex – as sex can actually, according to research, make us less stressed and therefore fall asleep quicker).