23 Reasons You're Tired All the Time

Plug the hole in your energy bucket once and for all.

a man sleeping at a desk with a laptop computer and a tablet in front of him

It's a question every person inevitably faces: "Why am I so tired?" According to the National Safety Council, 32 percent of employers admit that they've had accidents or close calls at work due to fatigued employees.

And while many people may be aware that they're not getting as much rest as they should, few are aware of just how serious their sleep deficit may be. In fact, according to a study conducted at the University of Chicago, people tend to vastly overestimate how much sleep they're actually getting, with study participants averaging 7.5 hours in bed, but just 6.1 hours sleeping. (That, by the way, is an entire hour less than the minimum doctor-recommended figure from the National Sleep Foundation.)

However, while a lack of sleep may be a major contributor to your persistent fatigue, it's not the only possible culprit. In fact, there are a wealth of factors that can contribute to those bleary-eyed days and exhausted nights. If you're fighting an uphill battle against a seemingly-unshakable sleepiness, discover these 23 reasons you're tired all the time.

Your thyroid isn't functioning properly.

reasons you're tired

The thyroid—the butterfly-shaped gland at the base of your neck—is one of those body parts people rarely think about until they realize something's amiss. However, when it comes to fatigue, a misfiring thyroid might be the reason you're struggling to stay alert throughout the day.

"An imbalance in thyroid hormones can result in hypothyroidism, which can cause fatigue," says Dr. Janette Nesheiwat, M.D. So, how does one determine if their thyroid is behind their persistent fatigue? "This is found by seeing your doctor, having blood work done—and may possibly require medication."

You're not getting adequate exercise.

reasons you're tired

Need more incentive to hit the gym? If you're feeling fatigued throughout the day, a little exercise could help you bounce back. The results of a study conducted at Seattle's Fred Hutchinson Cancer Research Center reveal that older women who increased the amount of exercise they got during daylight hours also increased their sleep duration and experienced fewer episodes of falling asleep during the day.

You have an insufficient nutrient intake.

woman at work eating lunch at her desk

If you're loading up on nutrient-light junk food to keep your energy levels up during the day, you're doing yourself a disservice. "Insufficient iron, B12, and folate levels will result in fatigue as your body needs these nutrients for energy metabolism," says Dr. Nesheiwat. The good news? Combatting diet-related fatigue is simple: "Eat green veggies, lean meat, and whole grains."

You keep your room too warm.

reasons you're tired

While spending time in a warm room may make you feel ready to hit the hay, dialing up the thermostat might be the very reason you're staying tired throughout the day. Researchers at the University of South Australia's Center for Sleep Research have found that people with trouble sleeping may have more difficulty regulating their body temperature during sleep, meaning that a warm room may cause those with sleep-onset insomnia to overheat, making the condition worse, and contributing to daytime fatigue.

So, what's the ideal sleep temperature? Research suggests that temperatures in the mid-60s Fahrenheit are more conducive to enjoying adequate rest.

You watch TV before bed.

reasons you're tired

Watching a show or two in bed may seem like a relaxing end to your day, but using your TV, computer, or phone too close to bedtime could be the reason you can't shake that fatigue after you wake up.

According to research conducted at Rensselaer Polytechnic Institute, individuals who were exposed to blue light produced less of the sleep-inducing hormone melatonin, making them more susceptible to sleep that's poor in both quality and duration, and, as a result, tiredness.

You're dehydrated.

reasons you're tired

While drinking too much water before bed may have you running to the bathroom in the middle of the night, having too little to drink can have an equally detrimental effect on your energy level.

"Dehydration, a very common cause of fatigue, can easily be corrected by drinking a sufficient amount of water and avoiding excess caffeine and alcohol," says Dr. Nesheiwat. Just make sure to slow down your consumption a few hours before bedtime and you should enjoy more restful sleep.

You're stressed out.

Stressed out man

While, in some instances, stress can make you feel almost jittery, it may also be one of the reasons you're tired all the time. According to the results of a study published in BMC Psychiatry, stress—particularly that of the work variety—and fatigue are inextricably intertwined, so if you're eager to have more energy on a regular basis, it might be time to think about using those vacation days.

You sleep with pets in your room.

reasons you're tired

Curling up with your pet may be nice in theory, but in practice, it could be the reason for that fatigue you can't ditch. Research conducted by the Mayo Clinic reveals that individuals who hit the hay with a dog in their bed had less restful sleep than those who didn't. The good news? Keeping your pup on their own bed nearby may actually help you get better rest.

Your partner snores.

reasons you're tired

Even if you don't realize they're doing it, your partner's snoring can be a surprising determinant of how tired you feel in the morning. Those loud noises your partner makes during sleep can easily wake you up throughout the night without you knowing it, leading to serious fatigue when it's time to wake up.

You have the flu.

Habits That Increase Flu Risk

If you want yet another reason to be extra diligent about washing your hands this winter, consider this: before you even realize you're sick, the flu could be sapping your energy. "The flu can cause fatigue," cautions Dr. Nesheiwat. "This virus infiltrates our body and requires rest, hydration, and sometimes antivirals to get better."

You drink alcohol frequently.

reasons you're tired

As a central nervous system depressant, alcohol can make you feel pretty tired, no matter when you consume it. However, the more you drink, the more likely you are to be dealing with the full-day effects of fatigue. According to a study published in Neurology, regular alcohol consumption is associated with probable REM sleep behavior disorder, with heavy drinkers hit the hardest, leading to greater fatigue after a night of tossing and turning.

You have anemia.

iron deficiency blood test

That lack of iron in your diet could be a major contributor to your persistent fatigue. While some cases of anemia are mild enough to go unnoticed, for those with more severe forms of the condition, fatigue is one of the earliest tells. The good news? Doctor-approved iron supplementation and dietary changes can help improve your energy levels in no time.

You have sleep apnea.

reasons you're always tired

Sleep apnea, a condition in which you suddenly stop breathing during sleep, can be a major contributor to fatigue during daylight hours, too. And while there are some factors you can control when it comes to sleep apnea, like shedding excess weight, the condition is also associated with those you can't control, including age, sex, hypothyroidism, and jaw shape. The good news? According to the results of a study published in the journal Sleep, using a CPAP machine significantly reduced fatigue among those with sleep apnea.

You have restless legs syndrome.

reasons you're tired

If your legs won't stop moving long after you've gotten in bed, don't be surprised when you're seriously fatigued throughout the day. Restless legs syndrome—the likelihood of which develops with age—and comorbidities like fibromyalgia keep your legs moving involuntarily throughout the night, making it harder to get adequate rest and leaving you fatigued by the time morning rolls around.

You have mono.

woman sick in bed exposed to serious flu risk

While you may have imagined that your risk of catching mono was almost nil after your college years, that's far from the case. In fact, this common ailment could be the reasons you're always tired. "Infections are also a very common cause of fatigue," says Dr. Nesheiwat. "Mononucleosis, known as 'the kissing disease,' can cause extreme fatigue, [but] this usually goes away with time."

You're depressed.

depressed woman crying in bed

Depression can feel like enough of a burden as it is, and its side effects can only make you feel worse. One of the major side effects of depression is fatigue, and can make the condition even less bearable for many of its sufferers. The good news? Treatment can help reduce the life-altering effects of both.

You have a UTI.

Woman really needs to use the bathroom

That burning feeling you have when you go to the bathroom could be contributing to your persistent fatigue throughout the day. In addition to infections contributing to general fatigue, UTIs can increase the frequency with which you get up to use the bathroom during the night, shortening your sleep duration and making it harder to get adequate rest.

You take certain medications.

reasons you're tired

While some prescription medications can be true lifesavers, some of those pills your doctor prescribed could be the reason behind your frequent exhaustion. Medications like antidepressants, anti-anxiety medications, pain killers, and even stimulant medications to treat ADHD can either make you tired or contribute to poor sleep, making it difficult to wake feeling well-rested.

You have diabetes.

Woman with Diabetes

If you're chronically exhausted but can't figure out why, it's time to ask your doctor for a blood test. When your body isn't appropriately processing the sugar in your diet, you can find yourself fighting an uphill battle against hyperglycemia, a condition that is often accompanied by unshakable fatigue.

You have night terrors.

reasons you're tired

Unfortunately, sometimes fatigue and sleep problems go hand-in-hand, getting you into a cycle of sleeplessness that's hard to break. Night terrors, or nightmares in which you find yourself terrified and often unable to move, can be a major contributor to daytime fatigue. Sadly, fatigue can also increase your risk of night terrors, so if this cycle has you walking around in a fog all day, it's time to consult your doctor.

You're pregnant.

pregnant woman in bed

Ask anyone who's done it and they'll tell you that carrying a baby is hard work. Even if you haven't had your pregnancy confirmed by a doctor, you may already be experiencing symptoms like fatigue. As your progesterone levels rise during the first trimester of your pregnancy, your exhaustion can spike as well. Later in pregnancy, your inability to get comfortable in bed and those frequent trips to the bathroom can compound the issue.

You eat too much sugar.

reasons you're tired

If you're relying on sugary foods to help you through your energy lull, think again. As revealed by research published in the Journal of Personality and Social Psychology, people who ate high-sugar snacks felt increased energy for an hour following their consumption, only to report increased fatigue afterward.

You have low testosterone.

reasons you're tired

Your hormones and your energy levels are more interconnected than you might imagine. For some men, low testosterone is the culprit behind that fatigue that doesn't improve with rest. While only a physical and blood work can accurately tell you if you're dealing with diminished testosterone levels, if you're also experiencing mood changes, sexual dysfunction, and weight gain, it's definitely worth scheduling an appointment with your GP.

To discover more amazing secrets about living your best life, click here to follow us on Instagram!

Best Life
Live smarter, look better,​ and live your life to the absolute fullest.
Get Our Newsletter Every Day!
Enter your email address to get the best tips and advice.
close modal
close modal