(From Pulse on-line learning module)
- Mild: <2.88
- Moderate: 2.88 – 3.4
- Severe: >3.4
If the level is mild or moderate (i.e. 3.4 or less) and the patient is asymptomatic, repeat within the next week. Fasting bloods may be more accurate (although, in practice, that could make it difficult to get a PTH level at the same time). Taking blood without a tourniquet can help but is tricky.
Patients with severe hypercalcaemia, or with calcium >3 who are symptomatic, should be admitted.
The most common causes are hyperparathyroidism and hypercalcaemia of malignancy; remember that these are not mutually exclusive and that it is not out of the question for them to co-exist. Hypercalcaemia of malignancy is not always secondary to bony mets; it may be secondary to humoral secretion of parathyroid hormone-related peptide.