Hyperparathyroidism is where the parathyroid glands produce too much PTH. This causes blood calcium levels to rise (hypercalcaemia) and blood phosphorus levels to fall (hypophosphataemia).


Hyperparathyroidism doesn't always cause symptoms. It's often diagnosed while having a blood test for another unrelated problem.

When high calciumlevels do cause symptoms, they can be mild or general and include:

  • depression
  • fatigue
  • feeling thirsty and passing a lot of urine
  • feeling sick and losing your appetite
  • muscle weakness
  • constipation
  • tummy pain
  • loss of concentration
  • mild confusion

Left untreated,high blood levels of calcium can cause:

  • vomiting
  • drowsiness
  • dehydration
  • confusion
  • muscle spasms
  • bone pain or tenderness
  • irregular heart beat
  • high blood pressure (hypertension)

In severe cases, high calciumlevels can lead to loss of consciousness and coma . They can also cause a number of other possible complications (see below) .

The severity of your symptoms doesn't always match up to the calcium level in your blood. For example, some people with a slightly raised calcium level may have symptoms while others with high levels can have little or no symptoms. Symptoms depend, in part, on the rate with which calcium levels become raised.


There are two main types of hyperparathyroidism. They are:

  • primary when one or more of the parathyroid glands is enlarged or overactive, for reasons explained below, and the abnormality causing it is within the gland itself
  • secondary when nothing is wrong with the gland, but there's a condition, such as kidney failure or vitamin D deficiency , that lowers calcium; the body reacts by producing extra parathyroid hormone to stop calcium levels from falling to a very low level

Rarely, when secondary hyperparathyroidism goes untreated for too long, the gland remains overactive all the time. This is known as tertiary hyperparathyroidism. It's most commonly seen in people who've had kidney failure for a long time.

The main cause of primary hyperparathyroidism is a non-cancerous tumour called an adenoma growing on one of the parathyroid glands, causing it to become overactive. Primary hyperparathyroidism may also result from two or more of the glands becoming enlarged (hyperplasia).

In rare cases, primary hyperparathyroidism can occur as a result of inherited genes and the diagnosis is made at a younger age. Very rarely, it's caused by cancer of a parathyroid gland.

Who's affected

Most cases of hyperparathyroidism occur in people with no family history of the condition. Only about 5% of cases can be linked to an inherited problem.

Women are twice as likely as men to develop hyperparathyroidism and the risk increases with age.


Hyperparathyroidism is diagnosed after a blood test shows:

  • high levels of PTH
  • high levels of blood calcium
  • low levels of phosphorus

A DEXA scan (a bone density X-ray) can help detect bone loss, fractures or bone softening, and X-rays , CT scans or ultrasound scans may show calcium deposits or kidney stones. While scans may help plan management, they're not essential for the diagnosis of the condition, which is based on blood tests.


Primary hyperparathyroidism can only be treated with surgery to remove the adenoma from the parathyroid gland. Surgery is effective in curing about 97% of hyperparathyroidism cases.

Bisphosphonate medicines are sometimes used to lower very high calcium levels. It's usually given as an intravenous drip (directly into the vein). Bisphosphonates may also be used to treat osteoporosis.

Make sure you have a healthy, balanced diet . You don't need to avoid calcium altogether, and a lack of dietary calcium is more likely to lead to a loss of calcium from your skeleton, resulting in brittle bones ( osteoporosis ). However, you 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 (read more about treating chronic kidney disease ). In some people with secondary hyperparathyroidism caused by kidney disease, a tablet called cinacalcet may be used to help control the condition.


Complications of hyperparathyroidism are rare but include:

  • osteoporosis and bone fractures
  • kidney stones and blockage, and kidney damage or failure
  • peptic ulcers
  • pancreatitis (inflammation of the pancreas)

Content supplied by the NHS Website

Medically Reviewed by a doctor on 21 Dec 2018