Hypercalcaemia is a high level of calcium in the blood. It can be caused by a number of conditions and the condition itself can lead to other complications such as kidney stones, bone pain, gastrointestinal distress, excess urination and even mental illness. It often presents together with fatigue, anorexia and pancreatitis. Severe hypercalcaemia can lead to coma and heart attack.
The "horse" cause for hypercalcemia is primary hyperparathyroidism - it accounts for about 90% of cases. Less common causes are use of lithium, cancer, Vitamin D disorders, high bone-turnover disorders and kidney failure.
Even without knowing the underlying cause, hypercalcaemia should be treated with fluids (oral and intravenous), increased sale intake and diuretics. Urine production has to be monitored as very low levels can indicate very high potassium levels.