If you rely on countless cups of coffee to get through the workday, you're not alone.
Exhaustion is par for the course in our culture. One survey found that 76 percent of U.S. respondents feel tired at work many days of the week. Even Google assumes we're all nodding off at our keyboards: Type the query "Why am I..." into the search bar, and it instantly autofills with "so tired".
"Fatigue is a common complaint in my office," said internist Dana Corriel. But late-night Netflix binges aren't necessarily to blame, nor is sleep always the solution. As it's such a general symptom, fatigue could be a result of many illnesses, she said.
Below, health experts break down what could be at the root of your exhaustion, from health conditions to lifestyle factors:
1. You're not sleeping well enough.
It's not just about the quantity of your shut-eye, but also the quality. Insufficient sleep is probably the main cause of feeling tired for Americans, according to Noah Siegel, a sleep-medicine physician at the Massachusetts Eye and Ear Institute at Harvard University.
Seven to eight hours of shut-eye each night is the typical requirement for adults, but even if you're in bed for that amount of time (or longer), you may not be getting the restorative, refreshing sleep you need, he said.
"Many patients come to me saying they're in bed for nine hours, but still wake up sleepy," Siegel said. The culprit? Environmental disturbances, such as blue light from screens, ambient noise, hot or cold temperatures, an uncomfortable mattress, or restless pets or children in the bed are often to blame, he added.
Action plan: There are lots of ways to improve your sleep quality, Siegel said. Try to stick to a consistent sleep schedule, cut out caffeine and alcohol, keep your room cool and avoid screens before bed. For more tips, check out these ways to combat sleep deprivation.
2. You may have sleep apnoea.
Sleep apnoea, a disorder that causes shallow breathing or even pauses in breathing, can disrupt your sleep and affect the quality of your shut-eye. It stems from a partially blocked airway, Siegel said. This could be caused by enlarged tonsils, a small airway, being overweight or allergies.
Action plan: To treat sleep apnoea, you have to open up the airway located in the back of your throat. The most effective way to do so is a medical device called a CPAP, which blows pressured air to keep the airway open, Siegel said. Other options include surgical procedures to remove potential blockages and enlarge the airway, as well as other oral appliances. Losing weight, sleeping on your side and avoiding alcohol may help.
3. Your iron levels are low.
"Low iron levels affect how much oxygen reaches your tissues, and deprives them of the energy they need," Corriel said.
This is often accompanied by anaemia, but patients can still feel tired and have low iron levels without being in the anemic range. Other symptoms of iron deficiency include pale skin, brittle nails and dry skin, headaches and dizziness, chest pain or shortness of breath, cold hands and feet, inflammation or soreness of the tongue, and unusual cravings for ice, dirt or starch, said Madeline Basler, a nutritionist in New York.
Action plan: Eat more iron-rich foods. If you're an omnivore, go for items like oysters, clams, poultry and red meat. Your body absorbs animal sources better than plant sources, Basler said. But vegetarians and vegans can enjoy plant-based foods like white beans, spinach, lentils and fortified cereals.
4. You're deficient in vitamin B12.
"B12 is an essential vitamin found in meat, fish, poultry, eggs and milk," Corriel said. For this reason, some vegetarians – and especially vegans – tend to be deficient in this vitamin. It's necessary for the proper function and development of the brain, nerves, blood cells and other parts of the body.
Action plan: Repletion can be accomplished through various methods, but the most popular ones come in oral or injection forms, Corriel said.
5. You're eating too much sugar.
Although the body needs some sugar for energy, eating too much of the refined kind can cause unwanted consequences, such as weight gain, chronic disease and, of course, those dreaded "sugar crashes", which affect your mood and energy levels, said Atlanta-based psychiatrist Dion Metzger.
Action plan: Protein is the antidote to those crashes, helping to stabilise your blood sugar and prevent those spikes and dips in energy. Try to include more veggies and high-protein, low-fat foods in your diet, Metzger said, and fewer fried foods and sugary snacks like biscuits, cake and doughnuts.
You shouldn't cut out carbs entirely, though. "Carbs convert into glucose, which is our brain's preferred energy source," Basler added. Just be sure to choose the whole-grain kind.
6. You may have depression.
Fatigue, along with changes in sleep habits, are two of the main symptoms of depression, according to Metzger. Other signs that depression may be present include feeling unmotivated, no longer enjoying the things you used to find fun, and feeling hopeless.
Action plan: Talk to your doctor if you suspect you may be depressed. When diagnosed, depression can be treated with methods such as exercise, relaxation techniques, massage, cognitive behavioural therapy, and by various medications such as SSRIs and other classes of drugs.
7. You may have an underactive thyroid.
The thyroid is a butterfly-shaped gland at the base the neck that produces hormones that regulate metabolism. If your thyroid hormone levels are low, you may experience fatigue, Corriel said. Other signs of thyroid dysfunction include feeling cold, feeling down, constipation, dry skin, brittle nails and hair changes.
Action plan: A simple blood test can determine whether your thyroid levels are off, Corriel said. The typical course of treatment includes a daily dose of a synthetic thyroid hormone, which mimics your body's natural thyroid hormone.
8. You don't get enough exercise.
You may not use up much energy being a couch potato, but a lack of movement ironically may lower your energy levels overall.
"Leading a sedentary life can often lead to feeling fatigue," Corriel said. "Our bodies need movement, and the physical inactivity negatively affects our muscles and our emotional well-being."
Action plan: "Strenuous, aerobic exercise helps promote good quality sleep, and in return better quality sleep will improve performance, both physical and mental," Siegel said. He suggested aiming for 30 minutes of aerobic exercise six days per week.
9. Your hormones may be out of whack.
In men, low testosterone levels can cause feelings of tiredness, Siegel noted. For both men and women, low cortisol levels can lead to fatigue. In women, elevated levels of estrogen and not enough progesterone can make you tired and moody, said Alissa Vitti, an integrative nutritionist, author of "WomanCode" and founder of FLOliving.com.
Action plan: See your doctor for a test (typically using either your blood or saliva), which can help determine your plan of treatment.
10. You may have seasonal affective disorder.
If you tend to feel more exhausted during the winter months, it may not be coincidental. People with seasonal affective disorder – SAD – exhibit depressive symptoms, including fatigue, as a result of less light exposure during shorter winter days, said Siegel.
Action plan: Light boxes, such as this LED lamp, can be helpful in treating SAD symptoms, Siegel said.
11. You might have diabetes.
If you have Type 2 diabetes, you may experience fatigue along with other symptoms such as increased urination and thirst, feeling hungry, blurred vision and dry skin, Corriel said.
Action plan: See your doctor to screen for diabetes; usually a test involving a fasting morning blood-sugar level.
Ultimately, as with all health issues, it's best to check with your primary care physician if you're dealing with chronic fatigue or you're feeling more tired than normal.
"The key to finding the right diagnosis is visiting a qualified professional, such as your trusted doctor, who thoroughly assesses you in order to find the cause," Corriel concluded.