CAUSES OF HYPERCALCEMIA

CAUSES OF HYPERCALCEMIA
Harrison 17th, AIIMS Nov 2007 Q

Excessive PTH production

Primary hyperparathyroidism (adenoma, hyperplasia, rarely carcinoma)

Tertiary hyperparathyroidism (long-term stimulation of PTH secretion in renal insufficiency)

Ectopic PTH secretion (very rare)

Inactivating mutations in the CaSR (FHH)

Alterations in CaSR function (lithium therapy)

Hypercalcemia of malignancy

Overproduction of PTHrP (many solid tumors)

Lytic skeletal metastases (breast, myeloma)

Excessive 1,25(OH)2D production

Granulomatous diseases (sarcoidosis, tuberculosis, silicosis)

Lymphomas

Vitamin D intoxication

Primary increase in bone resorption

Hyperthyroidism

Immobilization

Excessive calcium intake

Milk-alkali syndrome

Total parenteral nutrition

Other causes

Endocrine disorders (adrenal insufficiency, pheochromocytoma, VIPoma)

Medications (thiazides, vitamin A, antiestrogens)

Note: CaSR, calcium sensor receptor; FHH, familial hypocalciuric hypercalcemia; PTH, parathyroid hormone; PTHrP, PTH-related peptide.

Additions:-

**William's Syndrome causes hypercalcemia d/t increased sensitivity to Vitamin D, it is also called as Idiopathic Hypercalcemia of Infancy.

**Increased Bone turnover has also been mentioned for Vitamin A Intoxication and for Thiazides.

pgmeenotesby dv.