ICD-10 Diagnosis Code E21

Hyperparathyroidism and other disorders of parathyroid gland

Diagnosis Code E21

ICD-10: E21
Short Description: Hyperparathyroidism and other disorders of parathyroid gland
Long Description: Hyperparathyroidism and other disorders of parathyroid gland
This is the 2017 version of the ICD-10-CM diagnosis code E21

Not Valid for Submission
The code E21 is a "header" and not valid for submission for HIPAA-covered transactions.

Code Classification
  • Endocrine, nutritional and metabolic diseases (E00–E90)
    • Disorders of other endocrine glands (E20-E35)
      • Hyperparathyroidism and other disorders of parathyroid gland (E21)

Information for Medical Professionals

Index of Diseases and Injuries
References found for the code E21 in the Index of Diseases and Injuries:


Information for Patients


Parathyroid Disorders

Most people have four pea-sized glands, called parathyroid glands, on the thyroid gland in the neck. Though their names are similar, the thyroid and parathyroid glands are completely different. The parathyroid glands make parathyroid hormone (PTH), which helps your body keep the right balance of calcium and phosphorous.

If your parathyroid glands make too much or too little hormone, it disrupts this balance. If they secrete extra PTH, you have hyperparathyroidism, and your blood calcium rises. In many cases, a benign tumor on a parathyroid gland makes it overactive. Or, the extra hormones can come from enlarged parathyroid glands. Very rarely, the cause is cancer.

If you do not have enough PTH, you have hypoparathyroidism. Your blood will have too little calcium and too much phosphorous. Causes include injury to the glands, endocrine disorders, or genetic conditions. Treatment is aimed at restoring the balance of calcium and phosphorous.

NIH: National Institute of Diabetes and Digestive and Kidney Diseases

  • Calcium - ionized
  • Calcium - urine
  • Calcium blood test
  • Hypercalcemia - discharge
  • Hyperparathyroidism
  • Hypoparathyroidism
  • Parathyroid adenoma
  • Parathyroid biopsy
  • Parathyroid cancer
  • Parathyroid gland removal
  • Parathyroid hormone (PTH) blood test


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