Hypoparathyroidism

Hypoparathyroidism means the parathyroid glands produce too little PTH. This causes blood calcium levels to fall (hypocalcaemia) and blood phosphorus levels to rise (hyperphosphataemia).

You may need to take supplements for life to restore these levels. This could make you feel ill and cause your calcium level to fall even further, so it's important to remain calm.

Many symptoms listed above aren't specific to hypoparathyroidism. They can also be caused by other conditions.

Causes

Hypoparathyroidismis most commonly caused by accidental injury to the parathyroid glands during head and neck surgery. In about 12% of people undergoing surgery it lasts for only a short time, with less than 3% having permanent hypoparathyroidism.

Other causes include:

• destruction of the parathyroid glandsby the immune system in people with autoimmune diseases, where the body mistakenly attacks its own tissues
• radiation therapy to the neck for thyroid cancer
• surgical removal of the parathyroid glands as a result of cancer
• low blood magnesium levels for example due to alcohol misuse

Who's affected

You're more likely to develop hypoparathyroidism if you:

• have had recent thyroid or neck surgery
• have a family history of parathyroid disorder
• have Addison's disease

Children or adults with the inherited genetic disorder known as Di-George syndrome will also have hypoparathyroidism because their parathyroid glands are missing at birth.

Diagnosis

Hypoparathyroidism is diagnosed after a blood test shows:

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

If you have hypoparathyroidism an electrocardiogram (ECG) may show abnormal heart rhythms and a urine test will show high levels of urinary calcium (too much calcium leaving the body).

Treatment

Treatment aims to bring the blood levels of calcium and other minerals back to normal.

The normal calcium range is around 2.1-2.50 millimoles per litre (mmol/L). You should aim to maintain your blood calcium levels at 1.80-2.25 mmol/L.

Calcium carbonate and vitamin D supplements usually calcitriol (Rocaltrol) or alfacalcidol (One-Alpha) can be taken to restore these levels. With the exception of people who have short-lived hypoparathyroidism after neck surgery, these supplements usually have to be taken for life. You'll also need to have regular blood tests to monitor your blood levels. The aim of therapy is to relieve your symptoms and keep calcium in the near-normal or low-normal range.

It's also recommended that you follow a high-calcium, low-phosphorus diet.

Good sources of calcium include:

• milk, cheese and other dairy foods
• green leafy vegetables, such as broccoli, cabbage and okra, but not spinach
• soya beans
• tofu
• soya drinks with added calcium
• nuts
• bread and anything made with fortified flour
• fish where you eat the bones, such as sardines and pilchards

Phosphorus is found in:

• red meat
• dairy foods
• fish
• poultry
• bread
• rice
• oats

Ifyour blood calcium levels fall to a dangerously low level, or you keep having muscle spasms, you may need to be given calcium through a drip directly into your vein. Your heart rhythm will also be monitored until it's stable. You'll then continue treatment with supplements.

Complications

Hypoparathyroidism can sometimes lead to:

• stunted growth
• poorly developed teeth
• slow mental development
• cataracts

Sometimes, hypoparathyroidism can occur with other autoimmune conditions, such as Addison's disease and pernicious anaemia .

Excessive calcium replacement can cause complications, such as kidney stones .