Primary hyperparathyroidism

This code signifies a condition where one or more parathyroid glands produce excessive parathyroid hormone (PTH) due to an intrinsic glandular abnormality, leading to hypercalcemia. This overproduction of PTH is not a compensatory response to hypocalcemia but rather an autonomous dysfunction of the parathyroid tissue itself.

Apply this code when documentation confirms a diagnosis of primary hyperparathyroidism, typically evidenced by elevated serum calcium and PTH levels in the absence of other causes of hypercalcemia. This includes cases due to parathyroid adenoma, hyperplasia, or carcinoma.

• Differentiate from secondary hyperparathyroidism (E21.1), which is a compensatory response to chronic hypocalcemia (e.g., chronic kidney disease).
• Ensure documentation specifies "primary" to avoid confusion with other forms of hyperparathyroidism.
• Code any associated manifestations, such as nephrolithiasis (N20.0) or osteoporosis (M81.0-M81.8), as secondary diagnoses.