Lab Tests for Fatigue: What to Ask Your Clinician
If you’re constantly exhausted and can’t figure out why, a compact starter panel of blood work catches most treatable causes: complete blood count (CBC) with indices, comprehensive metabolic panel (CMP), TSH with reflex to free T4, ferritin or full iron studies, vitamin B12 and folate, 25-OH vitamin D, HbA1c, CRP or ESR, and a urinalysis. These nine tests cover anemia, thyroid dysfunction, blood sugar problems, iron deficiency, vitamin gaps, kidney and liver function, and inflammation, which together explain the overwhelming majority of medically fixable fatigue. The action is simple: get this panel drawn, then review every result with a clinician before you start supplementing or changing your diet based on a guess. The CDC’s evaluation guidance for ME/CFS is blunt about this: there’s no single blood test that diagnoses chronic fatigue, so labs work best as a systematic filter, not a magic answer. A peer-reviewed approach to chronic fatigue evaluation backs t...