This episode reviews how to evaluate and manage adults with extremely low or extremely high HDL cholesterol according to the 2025 AACE Algorithm.

• Identifies secondary causes of abnormal HDL, such as renal disease, low estrogen states, hyperandrogenism, medications (fibrates, TZDs, niacin, anti epileptics), alcohol excess, estrogen therapy, or pesticide exposure.

• Explains key genetic disorders linked to HDL extremes, including ABCA1 (Tangier disease), LCAT (fish eye disease), APOA1 deficiency, CETP deficiency, SCARB1 deficiency, LIPC deficiency, LIPG deficiency, and APOC3 variants.

• Summarizes diagnostic clues and next steps, such as examination for corneal clouding, orange tonsils, xanthomas, neuropathy, kidney evaluation, fasting lipid profile confirmation, and targeted genetic or family screening.