Hyperparathyroidism: symptoms, causes, tests and treatment

The NHS says many people with hyperparathyroidism have no, or very mild, symptoms, and may only find out they have it after tests for something else. Sometimes symptoms can have a big impact on daily life. Most of the symptoms come from the raised calcium level in the blood.

NICE guidance for primary hyperparathyroidism lists symptoms of hypercalcaemia (high calcium) as thirst, frequent or excessive urination and constipation, and asks doctors to consider measuring calcium in people with chronic non-specific symptoms. Complications of the condition are also a way it comes to light, including osteoporosis or a previous fragility fracture and kidney stones.

• Tiredness (NHS).

• Aches and pains, particularly in the joints, hands, arms, feet and legs (NHS).

• Muscle weakness (NHS).

• Feeling and being sick, loss of appetite and constipation (NHS).

• Tummy pain (NHS).

• Feeling thirsty all the time and peeing more than usual (NHS).

• Low mood and depression (NHS).

The NHS describes hyperparathyroidism as a condition that affects the amount of calcium in your body, and says this can affect your blood, bones and kidneys. It happens when the body produces too much parathyroid hormone (PTH). It is different from hypoparathyroidism, where there is not enough calcium in the body.

Calcium helps with keeping bones and teeth healthy, the NHS notes. That is why too much PTH can matter for the skeleton and kidneys as well as for how you feel day to day.

The NHS says producing too much PTH can be caused by a non-cancerous growth (adenoma) on the parathyroid glands in your neck, which is called primary hyperparathyroidism. It can also be caused by having low levels of calcium or vitamin D in your blood, or high levels of phosphates, which may be due to an underlying condition. This is called secondary hyperparathyroidism.

NICE separates primary hyperparathyroidism from familial hypocalciuric hypercalcaemia, an inherited condition that can look similar on blood tests. Specialists tell them apart by measuring how much calcium is passed in the urine.

The NHS says hyperparathyroidism can be diagnosed by testing samples of blood and pee, and that many people are first diagnosed when they are having tests for something else. Further tests and scans may then be recommended to check general health and plan treatment, including ultrasound scans, X-rays and bone density scans.

NICE guideline NG132 sets out the sequence in primary care. It recommends measuring albumin-adjusted serum calcium in people with symptoms of hypercalcaemia, osteoporosis or a fragility fracture, a kidney stone, or an incidental finding of calcium at 2.6 mmol/litre or above. A first high result is repeated. PTH is then measured if calcium is 2.6 mmol/litre or above on at least 2 separate occasions, or 2.5 mmol/litre or above with suspected primary hyperparathyroidism.

After a confirmed diagnosis, NICE recommends assessing symptoms and other conditions, measuring kidney function (eGFR or creatinine), a DXA bone density scan of the lumbar spine, distal radius and hip, and an ultrasound scan of the kidneys and urinary tract. Vitamin D is measured and supplements are offered if needed.

The NHS says that once diagnosed you will be referred to a specialist, and that treatment depends on the cause. If it is caused by a growth on your parathyroid glands, you will be offered surgery to remove part or all of the glands. If you do not want surgery, or it is not currently a suitable option, the specialist may offer medicine to help lower your calcium levels. If it is happening because of low calcium or vitamin D levels, treatment may include medicines and supplements.

NICE recommends referring people with confirmed primary hyperparathyroidism to a surgeon with expertise in parathyroid surgery if they have symptoms of hypercalcaemia, end-organ disease (kidney stones, fragility fractures or osteoporosis) or albumin-adjusted calcium of 2.85 mmol/litre or above, and says referral can be considered even without those features. Before surgery, imaging (usually ultrasound, sometimes a sestamibi scan) is offered where it will inform the surgical approach.

Where a single adenoma is seen on imaging, NICE says people are offered a choice of 4-gland exploration or focused parathyroidectomy. Calcium is checked 3 to 6 months after surgery, and a result in the reference range means the surgery is regarded as successful, followed by calcium checks once a year.

If surgery has been unsuccessful, is unsuitable or has been declined, NICE says to consider cinacalcet where calcium is high enough, and to consider a bisphosphonate to reduce fracture risk in people with increased fracture risk.

The NHS gives a clear warning here: do not make any changes to your diet to try to lower your calcium levels, unless you have been told to by your specialist. It says a change in your usual diet could make your symptoms worse or cause more serious problems. Ask your specialist or dietitian before cutting out calcium-containing foods or taking new supplements.

The NHS says that treatment is usually needed for hyperparathyroidism, and that getting treatment can stop it getting worse and prevent complications. If untreated, it can lead to osteoporosis (weaker bones that are more likely to break), kidney stones and high blood pressure, which can increase the risk of heart disease and stroke.

NICE says that people with primary hyperparathyroidism who have not had surgery are offered monitoring. This includes measuring calcium and kidney function once a year, considering a DXA scan at diagnosis and every 2 to 3 years if they have osteoporosis, and a kidney ultrasound if kidney stones are suspected.

NICE recommends offering parathyroid surgery to women who have primary hyperparathyroidism and are considering pregnancy. During pregnancy it recommends discussing management with a multidisciplinary team at a specialist centre, including an obstetrician, a physician with expertise in the condition, a surgeon, a midwife and an anaesthetist. It says not to offer cinacalcet or a bisphosphonate to pregnant women, and to be aware of an increased risk of hypertensive disease in pregnancy.

The NHS says to see a GP if you think you might have hyperparathyroidism, and to get checked if you have symptoms because treatment is usually needed. The NHS page does not list emergency symptoms. Seek urgent help in the usual way, through NHS 111 or 999, if you feel acutely unwell, for example with severe confusion or repeated vomiting.

On the NHS, the path is a GP blood test, referral to an endocrinologist or endocrine surgeon, imaging and then surgery or monitoring. Private endocrinology and parathyroid surgery are available for people who want quicker access, and the investigations NICE describes are the same. Ask for results to be shared with your GP so that yearly calcium monitoring after surgery is not missed.