What role does HDL play in fatigue?

The direct role of HDL (high-density lipoprotein) in fatigue is not well established by strong evidence. HDL is primarily known for its role in reverse cholesterol transport and cardiovascular protection. Some observational studies suggest that low HDL levels may be associated with chronic fatigue or systemic inflammation, but causality remains unclear. Fatigue is a complex symptom with many potential causes—sleep, stress, nutrition, exercise, and other biomarkers (e.g., iron, vitamin D, thyroid) are often more relevant. HDL alone is not a reliable predictor of fatigue. Mechanistic links (e.g., HDL's anti-inflammatory properties) are plausible but lack robust clinical confirmation. For persistent fatigue, a comprehensive medical evaluation is recommended. Evidence grade: weak/unclear, based on observational and mechanistic data. Caveat: consumer lab tests for HDL provide a snapshot, not a diagnosis.