What E21 covers · when clinicians use it
ICD-10 code E21 identifies Hyperparathyroidism and other disorders of parathyroid gland in the U.S. ICD-10-CM clinical and billing record set. It sits within the Endocrine, Nutritional & Metabolic chapter (E00–E89), the section that groups related diagnoses so providers, payers, and public-health agencies report them consistently. Clinicians and medical coders apply E21 when an encounter's findings match the Hyperparathyroidism and other disorders of parathyroid gland description, attaching it to the patient record so downstream insurance claims, payer audits, quality reporting, and epidemiological surveillance all reference the same standardized diagnosis. The ICD-10-CM is maintained by the Centers for Medicare & Medicaid Services and the CDC's National Center for Health Statistics, with an updated official code set released each U.S. fiscal year — always verify E21 against the current CMS/CDC release and your payer's documentation guidance before final use. This page summarizes documentation context for E21 and is a coding reference, not clinical, diagnostic, or billing advice.
E21 refers to Hyperparathyroidism and other disorders of parathyroid gland, a broad class of endocrine disorders involving the parathyroid, pituitary, adrenal, thymus, gonads, and other hormone-producing glands. These conditions may cause hormone excess or deficiency and affect growth, metabolism, reproduction, and immune regulation.
Symptoms
- Fatigue or weakness – Seen in adrenal, thyroid, or gonadal insufficiency
- Growth or pubertal delay – In pituitary or gonadal dysfunction
- Muscle cramps or spasms – Especially in hypoparathyroidism (E20)
- Hypertension – Linked with Cushing’s syndrome or hyperaldosteronism
- Infertility or menstrual irregularities – In ovarian or testicular dysfunction
- Weight changes – Rapid gain or loss from cortisol or thyroid imbalance
- Facial or body hair changes – In adrenal or pituitary hormone excess
Diagnosis
Diagnosis of Hyperparathyroidism and other disorders of parathyroid gland involves hormone panels (cortisol, ACTH, TSH, LH/FSH, aldosterone, calcium), stimulation or suppression testing, imaging (CT/MRI of glands), genetic testing, and physical examination. The exact workup depends on the suspected gland and hormone axis affected.
ICD10 Code Usage
ICD10 code E21 is used across endocrinology, pediatrics, internal medicine, and reproductive health to classify and manage endocrine gland disorders. It supports hormone therapy decisions, surgical intervention, reproductive planning, and chronic disease monitoring.
Related Codes
- E20 – Hypoparathyroidism
- E22 – Hyperfunction of pituitary gland
- E23 – Hypofunction and other disorders of the pituitary gland
- E24 – Cushing's syndrome
- E25 – Adrenogenital disorders
- E26 – Hyperaldosteronism
- E27 – Other disorders of adrenal gland
- E28 – Ovarian dysfunction
- E29 – Testicular dysfunction
- E30 – Disorders of puberty, not elsewhere classified
- E31 – Polyglandular dysfunction
- E32 – Diseases of thymus
- E34 – Other endocrine disorders
- E35 – Disorders of endocrine glands in diseases classified elsewhere
FAQs
Q1: What is ICD10 code E21?
A: This code classifies Hyperparathyroidism and other disorders of parathyroid gland, a disorder involving hormone-producing glands that regulate key physiological functions.
Q2: What causes these endocrine disorders?
A: Causes include tumors, autoimmune disease, genetic syndromes, trauma, or idiopathic dysfunction.
Q3: Are these conditions curable?
A: Some are treatable with hormone replacement or surgery; others require lifelong hormone regulation.
Q4: What are common treatments?
A: Hormone supplementation or suppression, surgery, radiotherapy, lifestyle changes, or genetic counseling.
Q5: Who manages these disorders?
A: Endocrinologists are primary, with support from reproductive specialists, pediatricians, neurologists, or surgeons depending on the gland involved.
Conclusion
ICD10 code E21 ensures the precise documentation of Hyperparathyroidism and other disorders of parathyroid gland. It helps clinicians tailor hormone management strategies, coordinate interdisciplinary care, and track long-term outcomes for a wide range of endocrine-related conditions.