Parathyroid hyperplasia is second only to adenoma as the most common cause of hyperparathyroidism. Symptoms are most likely to result from elevated serum calcium levels. Symptoms include nephrocalcinosis and nephrolithiasis. Studies that may help confirm a suspected diagnosis include ultrasonography, computed tomography, radionuclide scanning with thallium and/or technetium, and magnetic resonance imaging. Surgical treatment consists of excision of all but part of one parathyroid gland if all of the glands are enlarged.