Evaluate for underlying etiology/alternate diagnoses of symptoms
PTH- elevated
Calcium- elevated if primary, low if secondary
Phosphate- low in primary, high in secondary
Alk phos- elevated
Hyperparathyroidism
Addison's disease
Hypoparathyroidism
Calciphylaxis
Hypothyroidism
Excess vitamin D
Hyperthyroidism
Hypercalcemia of malignancy