Hyperparathyroidism (and hypoparathyroidism) are rare hormone disorders caused by the parathyroid glands in the neck producing too little (hypo) or too much (hyper) parathyroid hormone. In the latter the parathyroid glands (there are 4) produce too much PTH. This causes blood calcium levels to rise (hypercalcaemia) and blood phosphorus levels to fall (hypophosphataemia). Hyperparathyroidism is diagnosed via a blood test which may show high levels of PTH, high levels of blood calcium and low levels of phosphorus. Primary hyperparathyroidism can only be treated with surgery to remove the adenoma from the parathyroid gland. Following surgery, the patient should avoid a high-calcium diet and drink plenty of water to prevent dehydration.

Treatment of secondary hyperparathyroidism depends on the underlying cause. Kidney disease is the most common cause of secondary hyperparathyroidism. In some people where secondary hyperparathyroidism is caused by kidney disease, medication may be prescribed to manage the condition