Kidney stones – Diagnosis and treatment – Mayo Clinic

Some calcium phosphate stones are caused by overactive parathyroid glands, which are located on the four corners of your thyroid gland, just below your Adam’s apple. When these glands produce too much parathyroid hormone (hyperparathyroidism), your calcium levels can become too high and kidney stones may form as a result.

https://www.mayoclinic.org/diseases-conditions/kidney-stones/diagnosis-treatment/drc-20355759