Hyperparathyroidism & Calcium Disorders
Four tiny glands that control the calcium in your blood and bones.
What is it
Behind your thyroid sit four tiny parathyroid glands. They release parathyroid hormone, or PTH, which keeps the calcium in your blood within a narrow, healthy range — mainly by drawing calcium out of bone, absorbing more of it from food, and holding on to it in the kidneys.
In primary hyperparathyroidism, usually one of the four glands develops a small benign growth and releases too much PTH. Calcium is then steadily pulled out of the bones and into the blood. Many people feel entirely well and are diagnosed after a routine blood test; others notice tiredness, low mood, aches, constipation, excessive thirst, kidney stones or thinning bones. Low calcium, or hypoparathyroidism, is much less common and tends to cause tingling, cramps and muscle spasms.
How it is diagnosed
The diagnosis rests on measuring calcium and PTH together, since it is the combination of the two that identifies the problem — a calcium level alone can be misleading. We check vitamin D, kidney function and phosphate at the same time, as each affects the interpretation.
A 24-hour urine calcium collection helps distinguish primary hyperparathyroidism from conditions that resemble it but need no treatment. A DXA bone density scan shows whether the bones have already been affected, and imaging of the kidneys checks for stones.
If surgery is being considered, imaging is used to locate the overactive gland beforehand. This may involve ultrasound, a nuclear medicine scan, a CT scan or a PET scan, and more than one is
sometimes needed to be confident.
HbA1c
A result of 6.5 per cent or higher points to diabetes, while a result between 5.7 and 6.4 per cent sits in the prediabetes range.
Fasting Glucose
A fasting glucose test measures your blood sugar after an overnight fast.
Glucose Tolerance Test
An oral glucose tolerance test measures glucose before and again two hours after drinking a measured sugary drink.
Symptoms
Symptoms may include increased thirst, frequent urination, tiredness, blurred vision or cuts that are slow to heal.
Many people, however, feel entirely well in the early years, which is why testing rather than symptoms is what usually leads to the diagnosis.
How it is managed
Surgery to remove the single overactive gland is the only definitive cure, and it is usually a short and highly successful operation with a rapid recovery. It is the recommended option where there is evidence of effects on the bones or kidneys, where calcium is markedly raised, or in younger patients.
For mild cases, active monitoring with regular blood tests and periodic bone density scans may be all that is required, and many people remain stable for years. Staying well hydrated helps protect the kidneys in the meantime, and correcting vitamin D and attending to bone strength are part of routine care. Occasionally a tablet called cinacalcet is used to lower calcium where surgery is not
suitable.
Low calcium is treated differently, with calcium and activated vitamin D, and in selected cases with PTH replacement.
Alongside glucose, we monitor your HbA1c, blood pressure, cholesterol, kidney function, eyes and feet at regular intervals. This surveillance is what prevents complications
When to seek care promptly
Confusion, severe drowsiness, vomiting or extreme thirst in someone known to have high
calcium needs urgent assessment. So does numbness, tingling around the mouth or muscle
spasm in someone known to have low calcium.
Further reading
The Endocrine Society patient hub (hormone.org) and the NIDDK's endocrine disease pages
(niddk.nih.gov/health-information/endocrine-diseases) cover parathyroid and calcium disorders in
accessible detail.
Speak with our team
Our specialist endocrinologists diagnose and manage this condition every day. Request a
consultation with our team today.
