What role does hsCRP play in fatigue?

hsCRP (high-sensitivity C-reactive protein) is a well-established biomarker of low-grade systemic inflammation. Observational studies have found a moderate association between elevated hsCRP levels and fatigue, particularly in chronic inflammatory conditions (e.g., rheumatoid arthritis, autoimmune diseases) and also in otherwise healthy individuals with subclinical inflammation. However, the evidence is largely correlational; a direct causal role of hsCRP in fatigue has not been proven. Fatigue is multifactorial, involving psychological, metabolic, and lifestyle factors. In a direct-to-consumer test (e.g., MyBody-X), a single hsCRP value has limited utility without clinical context. Elevated hsCRP warrants medical follow-up to rule out infection, metabolic syndrome, or chronic disease. Interpretation should be integrated with symptoms, lifestyle, and other lab markers.