Always Exhausted? You Might Have One Of These Conditions

When your immune system is grappling with a disease, that fight requires energy.

So it’s probably not surprising that almost any disease you can name has fatigue listed among its symptoms.

“Fatigue may be the most common symptom people report, and in and of itself it can’t point you toward a diagnosis,” says Roxanne Sukol, M.D., a preventive medicine specialist at Cleveland Clinic.

Also complicating matters: “There are so many different ways to measure fatigue,” says Anne Cappola, M.D., of the University of Pennsylvania’s Division of Endocrinology, Diabetes, and Metabolism.