Distinguish the pathophysiology of hypercalcemia for various clinical states.
Please read through the Table and then the key features are excerpted after the table
| Condition | PTH | Calcium | PO4 | Cr. | Special feature |
| High oral intake | Low | + | N | N | Positive history |
| Primary hyperparathyroidism | High or N | ++ | Low | N | Kidney stones, psychic moans, Polyuria |
| Tertiary hyperparathyroidism | ++ | + | High due to renal failure unless treated | High | Long term renal failure causes it |
| Sarcoidosis | Low or N | + mediated by 1,25 alfa hydroxylase excess | + | N | Steroid suppressible |
| Tumor related | PTH suppressed because PTH related peptide is high | +++ | Low | N | Steroid suppressibility seen in Multiple myeloma, sarcoidosis but not in other tumors. |
High Ca & PO4 = Vitamin D toxicity
High ALP and normal Ca & PO4 = Paget's
High ALP and low Ca & PO4 = Rickets/Osteomalacia