Merrill Goodman

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...

Microbiome tests can be genuinely useful, but not in the way most marketing suggests. They’re best at giving you a snapshot of your gut bacteria, tracking how that ecosystem shifts after a diet change, and generating hypotheses your doctor can investigate further. What they are not, according to NIST’s testing of home gut microbiome kits , is a validated diagnostic tool ready for routine clinical use. Results still vary meaningfully from one provider to the next, and an international expert panel has called for further standardization before these tests earn a bigger role in patient care. Here’s what a test can realistically deliver: A one-time snapshot of which bacteria dominate your gut right now A way to monitor change after a diet, medication, or supplement shift A data point that helps a specialist form a clinical hypothesis, not a diagnosis Pro Tip: Decide your goal before you buy. If you want a rough baseline out of curiosity, order the test. If you want answe...

Functional lab testing is advanced biomarker testing designed to find root causes and subtle imbalances that routine annual labs often miss. It is worth pursuing if you have unresolved fatigue, gut symptoms, hormone shifts, or “normal” bloodwork that doesn’t match how you feel. The single most important thing to understand before you order anything is this: functional testing interprets your results against tighter, function-focused “optimal” ranges, not the wide reference ranges your standard lab uses to flag disease. That distinction changes everything about what a test can tell you. A routine panel asks, “Is this person sick?” A functional panel asks, “Where is this person’s biology drifting before it becomes a diagnosis?” Comprehensive functional panels typically run 50 to 150 or more biomarkers in a single draw, covering everything from micronutrient status to hormone metabolites. Specialty tests like the DUTCH hormone pa...

Certain beta glucans, specifically yeast and fungal β-1,3/1,6 forms, can prime your innate immune system by binding to receptors called Dectin-1 and CR3, triggering a cascade that makes macrophages, monocytes, and neutrophils more responsive to future threats. The strongest clinical signals come from randomized controlled trials showing reduced severity and duration of upper respiratory tract infections (URTIs) in athletes, older adults, and people prone to seasonal illness, though the overall human evidence remains heterogeneous and more large-scale trials are still needed. Research published in PMC confirms the receptor-level mechanisms are well established in preclinical models, with promising but not yet definitive human data. Here is what the current evidence supports: Yeast/fungal β-1,3/1,6 glucans are the forms most studied for immune modulation, with a systematic review of 34 RCTs reporting immunomodulation outcomes including reduced respiratory infection symptoms a...