Primary hyperparathyroidism
An overactive parathyroid gland pushes blood calcium too high. Usually caused by a single benign parathyroid adenoma, it is often silent and found on a routine high-calcium result — but over time it erodes bone and forms kidney stones.
What it is
The four parathyroid glands sit behind the thyroid and control blood calcium through parathyroid hormone (PTH). In primary hyperparathyroidism one gland (rarely more) becomes autonomous — usually a benign adenoma — and secretes PTH regardless of the calcium level. PTH pulls calcium out of bone, makes the kidney retain calcium and activates vitamin D, so blood calcium rises. The hallmark is high calcium with a PTH that is high or 'inappropriately normal' (it should be suppressed when calcium is high). Most cases today are mild and found incidentally on routine bloods. Left untended it thins bone (osteoporosis), causes kidney stones, and in severe cases affects mood, concentration and the gut — the classic 'stones, bones, groans and psychiatric moans'.
Key lab markers
- Calcium (corrected for albumin) — elevated; the trigger finding.
- PTH — high or inappropriately normal despite the high calcium (the diagnostic combination).
- Vitamin D — often low; deficiency must be corrected to interpret the picture.
- Phosphate — tends to be low.
- Creatinine / eGFR — assess kidney function and rule out secondary causes.
- 24-hour urine calcium — separates primary hyperparathyroidism from familial hypocalciuric hypercalcaemia.
- DEXA bone density, kidney ultrasound — assess end-organ damage.
Symptoms
- Often none — found on a routine calcium test
- Fatigue, low mood, poor concentration, irritability
- Excessive thirst and frequent urination
- Kidney stones (loin pain, blood in urine)
- Bone and joint aches, fragility fractures
- Constipation, nausea, abdominal pain
- Muscle weakness
Related lab panels
When to discuss with a doctor
A high corrected calcium should always be repeated and paired with PTH — the two together make the diagnosis. Very high calcium with confusion, marked thirst, vomiting or drowsiness is a hypercalcaemic emergency needing same-day care. For confirmed primary hyperparathyroidism, surgery to remove the overactive gland is the only cure and is recommended for symptoms, young age, high calcium, low bone density, kidney stones or reduced kidney function; milder cases can be monitored with calcium, kidney function and bone density. Vitamin D deficiency should be corrected. Mediora.AI flags the high-calcium / high-PTH combination and the bone and kidney markers worth watching; the surgical decision belongs with endocrinology.