You know you’re going to feel tired when you’ve stayed up late watching Netflix, have been up in the night with a newborn, or got up extra early to squeeze in a workout before work. But sometimes, tiredness has no obvious reason. And, even more annoying, sometimes this fatigue persists day after day.
This applies to everyone, but especially to women. Hormone differences mean women are more prone to sleep problems and the lack of energy they lead to, and things like periods, pregnancy, and menopause only add to your fatigue.
Below, we’ll dive into the common reasons you may be feeling tired as a woman and how you can use the RISE app to get more energy.
Disclaimer: The scientific literature uses gendered language when talking about female fatigue. We have used the terms “female” and “women” in this article, but this advice is for anyone who experiences fatigue and was assigned female at birth.
More research needs to be done into female fatigue and women’s health, but here’s what we do know about why you might be feeling tired.
One of the biggest causes of tiredness — for both men and women — is high sleep debt. Sleep debt is the running total of how much sleep you owe your body. It’s compared against your sleep need, the genetically determined amount of sleep you need.
We don’t all need a simple eight hours of sleep a night. In fact, one study suggests the average sleep need is 8 hours 40 minutes, plus or minus 10 minutes or so, but 13.5% of the population may need 9 hours or more sleep a night.
You might be feeling tired suddenly if you didn’t meet your sleep need last night, or have ongoing feelings of fatigue if you’re chronically sleep deprived.
And sleep loss may affect women more than men and in different ways. We look at whether or not women need more sleep than men here (we don't know).
A 2022 study found women felt sleepier during a night of sleep deprivation. These same women also had higher blood levels of neurofilament light chain, a biomarker used to detect neurodegeneration in Alzheimer’s disease.
Another 2022 study found better sleep quality in women — but not men — was linked to better mood and more intention to pursue career goals, status, and responsibility at work.
And for women who want to have kids, sleep loss can disrupt your reproductive hormones.
How do you know if you’re getting enough sleep? The RISE app can work out your individual sleep need and how much sleep debt you’re carrying each day.
RISE users on iOS 1.202 and above can click here to view their sleep need.
RISE users on iOS 1.202 and above can click here to view their sleep debt.
Your circadian rhythm is your body’s internal clock. It runs on a roughly 24-hour cycle and dictates everything from your sleep-wake cycle to your body temperature fluctuations to when certain hormones are produced.
When you’re out of sync with it, your mental and physical health take a hit, and your energy levels can plummet.
You might be out of sync with your circadian rhythm if:
Again, this is another problem that can make both men and women feel fatigued, but women may be more prone to it due to their fluctuating hormones.
Sometimes you don’t meet your sleep need because you stay up late voluntarily, or perhaps a child or job keeps you up. But other times, a sleep disorder is at play.
Anyone can be affected by these sleep disorders, but female stages of life can bring them on. When girls first get their periods, there’s a 2.75-fold increased risk for insomnia. You might experience insomnia before your period, or heavy periods can trigger a drop in iron levels, which can cause restless leg syndrome. You might also develop sleep-disordered breathing during pregnancy and sleep apnea during menopause.
Women have higher sleep reactivity, which means their sleep is more likely to be affected when they’re stressed. They may ruminate on problems, making them more vulnerable to insomnia, and constantly changing hormones and sleep patterns make the sleep disorder more likely. In fact, insomnia is 40% more prevalent in women than men.
It’s not just biology that makes women more prone to sleep problems, though. Socioeconomic factors — like the fact women often take on more childcare or work for less money — can contribute to stress and sleep problems.
If periods aren’t annoying enough, they could also be the reason you’re feeling so tired.
A 2020 study found total sleep time, deep sleep, and sleep efficiency (how long you spend actually sleeping in bed) decreased, and sleep onset latency (how long it takes to fall asleep) increased when women were on their periods.
It can be a vicious circle, too. Menstruation can cause sleep problems, but sleep problems can make period symptoms worse. A 2022 study found short sleep duration (defined here as less than six hours a night), poor sleep quality, fatigue, stress, and depression were all linked to heavier bleeding and irregular cycles.
Here’s how your period can be making you feel tired:
Unfortunately, many doctors don’t know enough about, or don’t think about, the menstrual cycle when treating patients.
You can learn more about why you’re feeling tired on your period, period insomnia, and how to sleep on your period here.
During pregnancy, hormonal changes can impact your sleep and energy levels. Progesterone increases in the first trimester, which can make you feel drowsy. You’re also likely to develop sleep-disordered breathing and insomnia during this time.
You may also find yourself waking up in the night to use the bathroom more frequently, or your baby’s movements may wake you up. Pregnancy symptoms — think heartburn, leg cramps, and back pain — can also make it harder to fall and stay asleep.
Aside from sleep, morning sickness, anxiety about pregnancy, and carrying extra weight can leave you feeling drained during the day.
The sleep problems don’t end when your baby’s born, either. A 2019 paper states 50% of women with probable insomnia during pregnancy continue to have symptoms two years after giving birth.
You may also be taking on more childcare duties, and therefore feel more fatigue and be up during the night more often.
To make matters worse, women who don’t get enough sleep in the six months after giving birth — something that can feel almost impossible when caring for a newborn — have been found to have more accelerated aging.
You can learn more about how to get energy when pregnant here, and if you’ve had or are planning on having a c-section, you can learn how to sleep after a c-section here.
Another stage of life that leaves women feeling more tired than usual is menopause. You may also feel tired during perimenopause — the transition period before menopause, which can begin four to six years before — and postmenopause.
There are a few reasons for this:
You can learn more about menopause sleep problems here, including how to fix them.
You’re obviously going to feel tired when you’re stuck in bed with the flu, but sometimes this tiredness can linger long after you feel recovered. Obvious symptoms may clear up, but your body can still be fighting an infection or recovering from the sleep debt you built up while ill.
COVID fatigue hits anyone, but research shows women are at a higher risk of COVID-related sleep disturbances. And long COVID can cause sleep disturbances and severe fatigue. You can learn how to get energy back after COVID here.
Mental health issues like anxiety and depression, and even just day-to-day stress, can impact your sleep and energy levels. And women are more prone to these things.
Women are twice as likely to develop depression than men, and they’re more likely to have an anxiety disorder. Mood disorders are more common in older women, too.
Hormonal mood swings are common through your menstrual cycle, pregnancy, and menopause, and women are also more at risk of seasonal affective disorder (SAD), which involves having a depressed mood and feeling low on energy during the winter months.
Societal demands may also add to female stress and sleep loss. You may be taking on more childcare duties, for example. A 2021 study found waking up during the night was more common in women, especially in early and middle adulthood when they could be raising kids.
Anxious thoughts keeping you up? We’ve covered how to sleep with anxiety here.
When you don’t give your body the healthy diet it needs, it won’t feel or function at its best.
Sugary snacks and simple carbs can spike your blood sugar levels, potentially giving you a temporary energy boost. But this comes with a sugar crash shortly after. A large lunch can make your natural afternoon dip in energy feel even worse. And diets high in added sugars, starch, and refined grains have also been linked to insomnia.
On the flip side, a balanced diet of complex carbs, proteins, fruits, and veggies can boost your energy levels.
Eating too close to bedtime can also keep you up at night, though, cutting into your sleep time. Check RISE for when you should have your last large meal of the day.
RISE users on iOS 1.202 and above can click here to set up their avoid late meals reminder.
Missing out on key vitamins and minerals can cause fatigue. These include:
Low vitamin C and zinc intake has also been linked to more depression and anxiety, which may contribute to sleep problems and low energy.
A doctor can test you for nutritional deficiencies and prescribe supplements if needed. Eat a varied healthy diet to minimize your risk.
Caffeine can, of course, make you feel more alert. But too much can keep you up past bedtime and wrack up your sleep debt. When caffeine wears off, you may be hit with a wave of tiredness. And it’s easy to build up a tolerance to caffeine, too, meaning when you have a cup less than you’re used to, you’ll feel sleepy.
Even simply drinking a cup of coffee too late in the day can keep you up past bedtime. To stop caffeine from keeping you awake, RISE can tell you when exactly to have your last coffee of the day. We cover when to have your last cup of coffee each day in more detail here.
RISE users on iOS 1.202 and above can click here to set up their limit caffeine reminder.
You don’t need to have skipped out on water all day to feel the effects. Even mild dehydration can cause fatigue, as well as disruptions in mood and lowered mental and physical performance.
Hydration may also affect your sleep. Short sleep duration, defined here as getting six hours, has been linked to higher odds of being dehydrated. Just be sure to get your water in earlier in the day to avoid waking up needing the bathroom too often during the night.
We all know we won’t be feeling our best when hungover, but alcohol affects your sleep, and therefore energy, in more ways than that.
Alcohol may make you feel sleepy and help you drift off, but it fragments your sleep, meaning you wake up often during the night and don’t get the restful sleep you need for maximum energy. It also changes your sleep architecture by suppressing REM sleep.
What’s more, binge drinking has been linked to insomnia, and alcohol can also cause you to snore and develop sleep apnea.
We’ve covered how long before bed you should stop drinking alcohol here.
The last thing on your mind when feeling tired is working out, but a lack of physical activity may be the cause of your sluggishness.
Exercise can not only help manage your weight and stress levels, it can also help you fall asleep at night. Just be sure to avoid intense exercise within an hour of bedtime, as this can have the opposite effect.
RISE can tell you when to avoid a workout and when your energy levels will be at their highest each day, so you can schedule in a gym session and make the most of this energy.
RISE users on iOS 1.202 and above can click here to set up their avoid late workouts reminder.
Your weight — and whether you’re gaining it or losing it — can make you feel drained.
Being overweight means your body has to work harder, and obesity is a risk factor for snoring, sleep apnea, type 2 diabetes, and depression. Being underweight means you get tired more easily and you’ll feel drained and weak.
And if you’re trying to shift a few pounds, weight loss might be behind your fatigue as you eat fewer calories and do more exercise. You can learn more about the best way to lose weight here.
When you take an over-the-counter sleep aid, you want it to make you feel sleepy, but this sleepiness can often last into the next morning — known as the hangover effect.
You can also become dependent on sleep aids, meaning you find it hard to get the sleep you need without them, which results in sleep debt and low energy.
Sleep aids can cause rebound insomnia, where your sleep is even worse after using them than it was before. And even when you get more sleep with sleep aids, it’s manufactured sleep, not the healthy natural sleep you need to feel maximum energy.
As women are more likely to be affected by insomnia, they may also find themselves reaching for sleep aids in an attempt to get some shut-eye.
The medication you’re taking may be another culprit behind your fatigue. Medications that come with fatigue as a side effect include:
Fatigue can hit anyone as a side effect, but medication can affect men and women differently. For example, the US Food and Drug Administration made Ambien lower the recommended dose of zolpidem (a sleep aid) for women because they were more at risk of next-morning impairment and car accidents.
It seems women eliminate zolpidem more slowly from their systems. So, it’s thought women may have different rates of absorption, metabolism, and excretion of other medications, too, and this could lead to different side effects, including fatigue.
Your thyroid gland is responsible for producing hormones to regulate your metabolism. When there’s a problem with it, your energy levels will take a hit. And these problems are more common in women.
Hypothyroidism, or underactive thyroid, when your thyroid doesn’t make enough hormones, can cause you to feel fatigued. It can also cause you to feel depressed and gain weight — both of which can impact your sleep.
Hyperthyroidism, or overactive thyroid, when your thyroid makes too much hormone, can cause you to feel irritable, weak, fatigued, and have trouble sleeping.
Essentially, if your thyroid isn’t on point, your energy levels won’t be either. Your healthcare provider can do a blood test to check for the correct levels of thyroid hormone.
Fatigue is a common symptom of conditions like:
Speak to a healthcare professional if you think you’re suffering from one of these health conditions.
Now you know the common causes of fatigue in women, it’s time to do something about them. The best way to boost your energy levels will depend on what’s causing your tiredness in the first place. For example, a lack of exercise or poor diet could be improved with lifestyle changes, whereas medical conditions need to be looked into by a healthcare professional.
But, don’t fret, you can work on improving two of the biggest things that determine your energy levels each day, and this can help in every situation.
These two things are:
Here’s what to do.
First, use RISE to work out your individual sleep need. Then, check how much sleep debt you have. The more sleep debt you’re carrying, the more tired you’re going to feel.
We recommend keeping sleep debt below five hours. Got more than that? You can pay sleep debt back by:
The RISE app can work out how much sleep debt you have and keep track of it as you pay it back. RISE can also guide you through 20+ sleep hygiene habits to help you drift off and get the sleep you need each night.
RISE users on iOS 1.202 and above can click here to view their sleep debt.
RISE users on iOS 1.202 and above can click here to set up their 20+ in-app habit notifications.
Being in sync with your circadian rhythm can boost your energy levels, help you fall asleep each night, and protect your mental wellness and physical health.
Here’s how to live in sync:
The RISE app predicts your circadian rhythm each day based on factors like your inferred light exposure and last night’s sleep times. You can then see when your body naturally wants to wake up, wind down for bed, and go to sleep, and sync up with these times.
RISE users on iOS 1.202 and above can click here to see their circadian rhythm on the Energy screen.
We’ve covered more ways you can get more energy here, including quick fixes for when you need an energy boost stat, and long-term changes to make a real difference to your fatigue.
Women can feel tired due to high sleep debt and being out of sync with their circadian rhythms. Hormone fluctuations during their periods, pregnancy, and menopause; taking hormonal contraceptives; and anxiety and depression can all cause fatigue, too.
To get more energy as a woman — or a man — work on lowering your sleep debt and getting in sync with your circadian rhythm. One win-win? This will make sleep disruptions like period pain and menopause hot flashes easier to deal with.
The RISE app can work out how much sleep debt you have and keep track of it as you pay it back. It can also predict your circadian rhythm each day, so you can easily sync your life up with it. And the app can guide you through 20+ sleep hygiene habits to help you get the good night’s sleep you need for more energy.
Reasons for fatigue in females include high sleep debt, being out of sync with your circadian rhythm, your menstrual cycle and period, pregnancy, menopause, hormonal contraceptives, poor diet, lack of exercise, stress and anxiety, medication side effects, and medical conditions like thyroid issues or anemia.
If you’re female and always tired, it could be down to high sleep debt, being out of sync with your circadian rhythm, your menstrual cycle and period, pregnancy, menopause, hormonal contraceptives, poor diet, lack of exercise, stress and anxiety, medication side effects, or a medical condition like thyroid issues or anemia.
Extreme fatigue in women can be caused by high sleep debt, being out of sync with your circadian rhythm, your menstrual cycle and period, pregnancy, menopause, hormonal contraceptives, poor diet, lack of exercise, stress and anxiety, medication side effects, and medical conditions like thyroid issues or anemia.
Sudden fatigue in females can be caused by not getting enough sleep the night before, not being in sync with your circadian rhythm, a blood sugar level crash, or hormone fluctuations during your menstrual cycle, pregnancy, and menopause.
Low energy levels in middle-aged women can be caused by high sleep debt, being out of sync with your circadian rhythm, your menstrual cycle and period (if you still get them), perimenopause and menopause, poor diet, lack of exercise, stress and anxiety, medication side effects, and medical conditions like thyroid issues or anemia.
To work out why you may be feeling so tired lately, use the RISE app to work out how much sleep debt you have and see whether you’ve been living in sync with your circadian rhythm. Sleep debt and circadian misalignment are two of the biggest things that determine your energy levels each day.
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