Many experts recommend surgery in the following circumstances: Serum calcium 1 mg / dL (0.25 mmol / L) greater than the upper limits of normal Calciuria > 400 mg / day (> 10 mmol / day) Creatinine clearance < 60 mL / min Peak bone density at the hip, lumbar spine, or radius 2.5 standard deviations below controls (T score = − 2.5) Age < 50 years The possibility of poor adherence with follow-up Surgery consists of removal of adenomatous glands.