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  3. E00–E89
  4. E20-E35
  5. Hyperparathyroidism and other disorders of parathyroid gland (E21)

Hyperparathyroidism and other disorders of parathyroid gland (E21)

ICD-10 codes in the E21 section identify specific disorders of the parathyroid gland, including various forms of hyperparathyroidism and other related conditions. These codes help accurately classify primary, secondary, and other types of hyperparathyroidism, as well as less common disorders affecting the parathyroid gland.

The E21.0 code covers primary hyperparathyroidism and its variants like familial, neonatal, and hyperparathyroidism-jaw tumor syndrome, often linked to excessive parathyroid activity. The E21.1 code designates secondary hyperparathyroidism, commonly caused by vitamin D deficiency or intestinal malabsorption. E21.2 includes other hyperparathyroidism types such as those induced by lithium therapy or ectopic hormone secretion. E21.3 is used when hyperparathyroidism is unspecified but may be associated with renal osteodystrophy or endocrine myopathy. The codes E21.4 and E21.5 cover other specified or unspecified parathyroid disorders like autoimmune parathyroiditis or parathyroid hematoma. Using these codes allows medical coders to precisely report conditions like hyperparathyroidism, known also as normocalcemic or familial hyperparathyroidism, aiding in accurate clinical documentation and billing.

Instructional Notations

Type 1 Excludes

A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.

  • adult osteomalacia M83
  • ectopic hyperparathyroidism E34.2
  • hungry bone syndrome E83.81
  • infantile and juvenile osteomalacia E55.0

Type 2 Excludes

A type 2 excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.

  • familial hypocalciuric hypercalcemia E83.52

Clinical Terms

The following clinical terms provide additional context, helping users better understand the clinical background and common associations for each diagnosis listed in this section. Including related terms alongside ICD-10-CM codes supports coders, billers, and healthcare professionals in improving accuracy, enhancing documentation, and facilitating research or patient education.

Hyperparathyroidism

A condition of abnormally elevated output of PARATHYROID HORMONE (or PTH) triggering responses that increase blood CALCIUM. It is characterized by HYPERCALCEMIA and BONE RESORPTION, eventually leading to bone diseases. PRIMARY HYPERPARATHYROIDISM is caused by parathyroid HYPERPLASIA or PARATHYROID NEOPLASMS. SECONDARY HYPERPARATHYROIDISM is increased PTH secretion in response to HYPOCALCEMIA, usually caused by chronic KIDNEY DISEASES.

Hyperparathyroidism, Primary

A condition of abnormally elevated output of PARATHYROID HORMONE due to parathyroid HYPERPLASIA or PARATHYROID NEOPLASMS. It is characterized by the combination of HYPERCALCEMIA, phosphaturia, elevated renal 1,25-DIHYDROXYVITAMIN D3 synthesis, and increased BONE RESORPTION.

Hyperparathyroidism, Secondary

Abnormally elevated PARATHYROID HORMONE secretion as a response to HYPOCALCEMIA. It is caused by chronic KIDNEY FAILURE or other abnormalities in the controls of bone and mineral metabolism, leading to various BONE DISEASES, such as RENAL OSTEODYSTROPHY.

Osteitis Fibrosa Cystica

A fibrous degeneration, cyst formation, and the presence of fibrous nodules in bone, usually due to HYPERPARATHYROIDISM.