Skip to content

What Your Fatigue Could Mean

Here's when to rest—and when to worry.

Are you tired? Or maybe the better question is: When aren't you tired? These days, the relentless news cycle and likely unbalanced work/life balance would wear anybody out.

But there's a difference between tiredness and fatigue—that recurrent feeling of being worn out from your head to your toes that doesn't improve with a full night's sleep. "Feeling tired is a common symptom associated with a long list of medical conditions," says Sherry Ross, MD, an OB/GYN at Providence Saint John's Health Center in Santa Monica, California. "There are many causes of chronic fatigue, including infections, stress, trauma, immune disorders and depression." 

Eat This, Not That! Health asked the experts what fatigue can mean, and what you should do if you're experiencing it. It's advice you won't want to sleep on.


You Have Adrenal Fatigue


"'Adrenal fatigue' is often used to describe the feeling of being excessively tired or fatigued, along with other symptoms attributed to the adrenal gland," says Ross. "Stress is thought to cause adrenal fatigue symptoms, including extreme fatigue even after a great night's sleep and trouble thinking clearly or finishing a task."

The Rx: Ross points out that adrenal fatigue isn't an official medical diagnosis. But if you're experiencing chronic fatigue that doesn't get better with rest, it's worth seeing a doctor and looking at habits—including stressors, diet, sleep patterns and mental health—that might be wearing you down. 


You Have An Infection

Microscopic image of a blood slide. Mononucleosis. Lymphocytes and monocytes are stained violet, red blood cells are red.

Fatigue can also be a sign of infection with a virus or bacteria, including Epstein-Barr, enterovirus, Rubella, candida albicans, mycoplasma and HIV, says Ross.

The Rx: See your doctor and describe your symptoms thoroughly, so he or she can order appropriate tests if necessary.


You're Burnt Out

Overworked businesswoman with many jobs, looking at pile of documents with bored expression

If you're experiencing burnout—a condition caused by extreme stress and high ideals—at work, you might be physically, mentally or emotionally exhausted (or any combination of the three). You might feel drained, unable to cope, sad and extremely tired. 

The Rx: Burnout may be a symptom of depression. Ask yourself if you're feeling negative about your life or just your work situation. If it's the former, you might be depressed. In either case, consulting your doctor or a mental health professional can get you back on track.  


You Have Low Testosterone

testosterone hormone test result with blood sample tube

If you're a man over 40 and experiencing recurrent fatigue, ask your doctor about getting your testosterone level checked. This key male hormone declines about 1 percent a year after 40, and that can bring on symptoms and health risks. "Physical manifestations of low testosterone may include fatigue, weight gain, osteoporosis, and cardiovascular disease, which can lead to a heart attack or stroke," says S. Adam Ramin, MD, urologist and medical director of Urology Cancer Specialists in Los Angeles.

The Rx: Consult your doctor about getting your testosterone level checked, which is done by a simple blood test in the early morning when hormone levels are high. A deficiency could be addressed with testosterone replacement therapy (TRT).


You're Dehydrated

Young man suffering from strong headache or migraine sitting with glass of water in the kitchen, millennial guy feeling intoxication and pain touching aching head

"Dehydration is one of the most common causes of fatigue and affects nearly everyone," says Dr. Thanu Jeyapalan, CSCS, FCE, DC, of the Yorkville Sports Medicine Clinic in Toronto. "Your body relies on water for many physiological processes, including producing energy and delivering nutrients throughout your system."

The Rx: The experts at Harvard Medical School recommend drinking four to six cups of water a day.

RELATED: 30 Ways Tap Water Could Ruin Your Health


You Have A Thyroid Imbalance

doctor examines with her fingers, palpates her neck and lymph nodes

In hypothyroidism (or underactive thyroid), the thyroid doesn't make enough of the hormones necessary to keep the body functioning optimally.  "Patients with hypothyroidism may experience symptoms such as fatigue or sluggishness, cold intolerance, constipation, hair loss, and weight gain," says Melanie Goldfarb, MD, endocrine surgeon at Providence Saint John's Health Center in Santa Monica, California. 

The Rx: Your doctor can check your hormone levels with a simple blood test. Imbalances can be treated with medication.


You Could Have A-Fib

ekg ecg heart test with stethoscope

The American Heart Association estimates that nearly 3 million Americans currently have atrial fibrillation (A-Fib), an irregular heartbeat that could reduce the heart's pumping efficiency and lead to heart failure, angina and stroke. "Common symptoms include fatigue, symptoms of rapid or irregular heart action, palpitation, lightheadedness, and shortness of breath," says Shephal Doshi, MD, director of cardiac electrophysiology at Providence Saint John's Health Center in Santa Monica, California.

The Rx: If you're experiencing A-Fib symptoms, talk to your doctor, who can run basic tests like an ECG or refer you to a cardiologist, who may prescribe medication or other therapies.


You're Not Getting Enough Sleep

woman cannot sleep with two pillows over face

"Patients often come to doctors complaining of feeling tired all the time. I generally see two or three patients with this complaint every week," says Dr. Laurence Gerlis, MA, MB, BChir, CEO and lead clinician of Same Day Doctor in London. "Very often, the history shows that people are actually not getting enough sleep, or the sleep quality is poor. It's surprising how patients don't connect the fact that they're feeling tired with the observation that they're getting less than seven hours of sleep per night."

The Rx: Experts including the National Sleep Foundation say that adults should get seven to nine hours of quality sleep each night.

RELATED: 40 Surprising Facts You Didn't Know About Your Sleep


You're Drinking Too Much

A couple makes a toast with two glasses of whiskey

"Alcohol and drug consumption may also affect fatigue. In particular, alcohol prevents one having a natural sleep," says Gerlis. Alcohol might seem like an effective way to relax yourself into sleep, but consuming alcoholic beverages too close to bed actually hinders rest. Alcohol actually shortens the time you're in deep (REM) sleep, which makes shuteye less restorative and can leave you feeling fatigued the next day. 

The Rx: Stick to one to two drinks nightly, and don't use booze as a sleep aid — it's counterproductive.


You're Anemic

Woman anemia

 "People with fatigue who've had digestive issues — as well as women with or without digestive problems — I would suspect have anemia," says Carol Thelen, CRNP, a certified nurse practitioner with Mercy Medical Center in Lutherville, Maryland. That condition, in which the body doesn't make enough red blood cells to carry oxygen to the body's tissues, can leave you feeling chronically tired.

The Rx: Consult your doctor, who can check your red blood cell count with a simple test.


You're Depressed

Sad thoughtful teen girl sits on chair feels depressed

"Sometimes fatigue isn't necessarily due to a physical medical condition," says Greta Aronson, LPC, a licensed professional counselor in Kansas City, Missouri. "If you're finding yourself constantly fatigued, be sure to check in with your mood. Depression is marked by a consistent low mood and loss of interest in activities, and another classic indicator is fatigue or loss of energy nearly every day." Depressive mood and fatigue have a very circular and destructive relationship, so it's important that you begin taking steps toward mood improvement when you start to notice these signs.

The Rx: "I always recommend to my clients to focus initially on eating nutrient-dense foods, getting restorative sleep through good sleep hygiene, and moving your body," says Aronson. "Other ways to improve your mood and energy levels are to engage in social interactions and try thinking in a more productive, helpful way during day-to-day situations. If you feel like you need further help, contact a therapist in your area."


You're Eating Too Many Simple Carbs

Woman refusing to eat bread

"Most CEOs and entrepreneurs clients come to me with recurrent fatigue," says Erica Ballard, MS, CHC, a certified health coach based in Indianapolis. "I find all my clients who have regular fatigue are eating too much sugar or too many carbs for breakfast and lunch. As a result, spikes in blood sugar increase their cravings for more sugar. That results in them being heavier than they want, inflammation in their body and gut, and an inability to do their best work. If the pattern continues, obesity and the diseases that come with it—like heart disease and type 2 diabetes—are absolutely next." 

The Rx: Avoid simple carbs and processed foods such as pastries, cakes, cookies, bagels, white bread and sugar-sweetened beverages. Complex carbs and whole fruits and vegetables will give you long-lasting energy and keep blood sugar levels stable.


You're Deficient in Vitamins

Iron foods

"Iron is a mineral which helps carry oxygen throughout the body to give your cells and organs energy to function," says Kristin Heim, RD, a registered dietician at CHA Hollywood Presbyterian Medical Center in Los Angeles. "If your iron level is low, this may explain why you are feeling fatigued." 

The Rx: "Some ways to add iron to your diet are through meat, fish, poultry, and fortified cereals," says Heim. "Add foods high in vitamin C—like citrus fruits, dark leafy greens and bell peppers—because they help the body absorb iron." 


It's a Symptom of Diabetes

doctor with glucometer and insulin pen device talking to male patient at medical office in hospital

Extreme fatigue is a common symptom of diabetes, caused by high blood sugar, dehydration or related kidney disease.  

The Rx: If you're experiencing fatigue along with other common diabetes symptoms such as frequent urination or extreme thirst, ask your doctor to test you for diabetes. 


It's a Symptom of Cancer

female physician checking male patients blood pressure at clinic

Extreme fatigue that doesn't get better with rest can be an early symptom of several cancers. "Cancer uses your body's nutrients to grow and advance, so those nutrients are no longer replenishing your body," explains Johns Hopkins Medicine. "This 'nutrient theft' can make you feel extremely tired."

The Rx: If you're experiencing serious fatigue that's recurrent and doesn't get better with rest, see your doctor for a thorough physical exam. 

RELATED: 30 Surprising Things That Affect Whether You May Get Cancer


You Have a Hormone Disorder

Hormone Replacement Therapy

In women, fatigue could be a sign of a high progesterone level. One of two female sex hormones (estrogen being the other), progesterone levels can fluctuate. When they're high, they induce the brain to produce more GABA, a neurotransmitter that relaxes the nervous system. That can make you tired.

The Rx: Your doctor can check your hormone levels with a simple blood test. Imbalances can be treated with medication.


You Could Have Sleep Apnea

Woman Covering Her Ears With Pillow While Man Snoring

Sleep apnea is an obstructive breathing condition in which you might stop breathing for up to a minute, before the brain wakes you up to start breathing again. This can happen several times a night, but because you're in deep sleep, you may not remember being awakened. Not only can sleep apnea cause you to be fatigued the next day because you didn't get quality rest, it's also associated with a higher risk of heart disease. 

The Rx: If you've been told you snore, talk with your healthcare provider about it.  


You Could Have Heart Disease

Woman suffering from chest pain indoor

According to the American Heart Association, fatigue can be a symptom of cardiovascular disease. Researchers found that people who tired too easily had a higher chance of having a heart attack or stroke in the near future.

The Rx: Eat right, exercise and keep your blood pressure in a healthy range. If you're experiencing recurrent fatigue, ask your healthcare provider to assess your heart health.

RELATED: 40 Things Cardiologists Do to Protect Their Hearts


You're Not Eating Enough Overall

frustrated confused tired scared displeased lady covering mouth with palms do not want to eat salad sitting at table looking at bowl

"Calories give us energy, and if we are trying to restrict our calories (i.e. for weight loss), we may be restricting them too much so that we experience chronic fatigue," says Amanda A. Kostro Miller, RD, LDN, a registered dietitian on the advisory board for Smart Healthy Living.

The Rx: "Work with a registered dietitian to determine your proper calorie amount," she says. Calorie needs vary according to your level of physical activity and other factors: According to the USDA, estimates range from 1,600 to 2,400 calories per day for women and 2,000 to 3,000 calories per day for men.


You're Not Eating Enough Good Carbs

Assortment of fresh fruits and vegetables

Trendy diets like keto have made carbs the enemy in the minds of many dieters. But if you aren't getting enough good carbs, your body will feel it. "Carbs are the body's preferred source of energy, so if we are not getting enough, you may feel fatigued," says Kostro Miller. In addition to dietary no-no's like snack foods, bakery items, candy and soda, "Carbs come from fruits, veggies, grains, pasta, potatoes and dairy," she says. "When someone is starting on a low carb diet, they sometimes say that they feel very fatigued, this is because they are restricting the body's preferred source of energy." 

The Rx: "According to the 2015-2020 Dietary Guidelines for Americans, carbohydrates should make up about 45 to 65% of your diet," says Kostro Miller. "Try to get most of your carbs from fruits, veggies, whole grains and low-fat dairy." And to live your happiest and healthiest life, don't miss these 40 Secrets Your Doctor Won't Tell You.

Michael Martin
Michael Martin is a New York City-based writer and editor. Read more about Michael