​“I’m just exhausted all the time, and I don’t know why. I used to have all kinds of energy. What do you think is wrong with me?” I get asked some version of that question several times a week. At any given time, there are just so many people who are tired or fatigued. Sorting out what’s causing it can be very tough, because there is such a huge list of possibilities. And often the cause is multifactorial – several factors working together to cause the weariness.

​Let’s at least dip our foot into how to sort out the underlying cause of this pervasive symptom. First we would spend a good bit of time on a history of the fatigue. For example, are there other symptoms that go along with the fatigue? If there is fever, or cough, or headache, or joint pains, or tearfulness than that points us in a specific direction. If the fatigue is an isolated symptom, that can be tougher, like trying to solve a crime without clues.
The timing of the fatigue is another helpful sign. Did it start abruptly a short time ago or did it sneak into life years ago? And, exactly what are they experiencing? Is it sleepiness, or weakness, or lack of motivation, or low energy? The exact description can point us in a particular direction.

​A physical exam will occasionally reveal a clue to the reason for fatigue. Are there swollen lymph nodes, or an enlarged liver, or abnormal sounds in the lungs? These kinds of findings are not terribly common in a person with general fatigue, but they’re worth taking a few minutes to have them checked.
Lab tests and other testing can be helpful if the history has given us a direction in which to explore.
Otherwise, just doing a raft of testing is usually very expensive and rather unhelpful. Some basic blood testing is the exception in that it does sometimes turn up one of the more common causes. For example, a small number of lab tests can readily screen for specific causes such as anemia (low red blood count), hypothyroidism, diabetes, or vitamin B-12 deficiency. Likewise, the blood tests will sometimes provide clues to point us in a direction, such as if the liver enzymes are substantially elevated or there are markers that indicate a lot of inflammation in the body.

When all is said and done and we’ve looked under every rock we can think of, what are we likely to find? One of the more common causes for fatigue is sleep deprivation. Either the person simply isn’t getting enough hours in bed, or the quality of their sleep is poor due to some sleep disorder such as sleep apnea, insomnia, or shift work. This is especially likely if they are tired even in the morning when they first get up. Other lifestyle factors such as lack of exercise, poor diet, obesity, or excess alcohol can also be major players in fatigue.

Another big category is in the arena of mental health. Sometimes fatigue is the way depression or chronic stress can show itself. Medication side effects can also play a roll, if a person is on sedating antihistamines or beta blockers or other meds that tend to contribute to fatigue.

Physical maladies such as those already named (anemia, diabetes and the like) and others we haven’t mentioned such as chronic arthritic diseases, heart disease, chronic lung diseases, urinary tract infection, low testosterone, adrenal insufficiency, hepatitis C, and mononucleosis, to name just a few, can also be the culprits. Devastating causes such as hidden cancers, leukemia, or lymphoma are quite rare but need to be thought about if other clues or lab results point us in that direction. If the fatigue has dragged on for months or years, the still much-debated diagnoses of chronic fatigue syndrome or fibromyalgia may be considered. In the end, even in carefully done medical studies of fatigue, after a thorough search has been completed, nearly a third have no clear, specific cause.

If you’re sick of being tired, you may want to work through things with your doctor to see if there is a definite cause that can be identified and treated. In the meantime, shoring up your habits by getting adequate sleep, good nutrition, and regular exercise can sometimes make a world of difference. At any rate, if your dragging along just keeps dragging on, it may be time to get it checked out.

Andrew Smith, MD is board-certified in Family Medicine and practices at 1503 East Lamar Alexander Parkway, Maryville. Contact him at 982-0835