Parathyroid and calcium disorders

The four parathyroid glands, behind the thyroid, control the calcium level in the blood through parathyroid hormone (PTH). The commonest cause of a raised calcium found on a routine blood test is primary hyperparathyroidism, where one gland becomes overactive, usually because of a small benign growth.

Many people are diagnosed after a routine blood test and feel well. Others have symptoms such as thirst, passing more urine, tiredness, low mood, or aches and pains.

What the assessment may involve

• Calcium and PTH, with vitamin D and kidney function
• A urine calcium test, to tell primary hyperparathyroidism from familial hypocalciuric hypercalcaemia, an inherited and usually harmless cause of a high calcium that doesn't need surgery
• A bone density (DXA) scan and a kidney ultrasound, to look for effects on bone and kidneys. Bone density scanning is not available at One Hatfield and is arranged at another centre.

Surgery or monitoring

Surgery is the only cure. NICE recommends referral to a parathyroid surgeon for people with symptoms of a high calcium, kidney stones, fragility fractures or osteoporosis, or a calcium level well above the normal range, and suggests referral can be considered for anyone with a confirmed diagnosis. Many people without these features choose monitoring instead. The decision is made with you, weighing what surgery would offer against monitoring in your situation.

Low calcium

Low calcium after neck surgery (hypoparathyroidism), or from low vitamin D or poor absorption, is also assessed.