Hyperparathyroidism is a primary or secondary condition caused by excessive amounts of parathyroid hormone (PTH).

There are primary and secondary forms of the condition:

• Primary is caused by a single parathyroid adenoma or hyperplasia of all four parathyroid glands. Parathyroid cancer is a rare cause. Predisposing factors include previous radiation to the neck or genetic predisposition.

• Secondary occurs in patients with renal failure, osteomalacia (Vitamin D deficiency), pseudohypoparathyroidism (a deficient response to parathyroid hormone), malabsorption syndromes, gastrectomy, and use of certain anticonvulsant medications.

There may be no symptoms, or the condition may be manifested by a variety of symptoms in the following categories:

• Renal demonstrated by the presence of calcium deposits or nephrolithiasis, polyuria, or nocturia.

• Skeletal demonstrated by constant lower back pain, bone tenderness, and frequent occurrence of fractures from bone deterioration.

• Gastrointestinal demonstrated by poor appetite, nausea, vomiting, difficulties with digestion, and constipation.

• Neuromuscular demonstrated by tiredness, muscle weakness and wasting, especially in the legs.

• Central Nervous System (CNS) demonstrated by a disturbance in physical activities that are linked to mental processes, personality disorders, loss of recent memory, depression, psychosis, stupor and, in some instances, coma.

• Other manifested by severe itching of the skin, problems with vision, excessive urine output, high blood pressure, and hardening of skin tissues.

The radioimmunoassay (RIA) test is done to identify the concentration of parathyroid hormone (PTH) in the blood. Increased serum calcium levels and decreased phosphorous levels help to confirm the diagnosis. X-rays may show various unfavorable changes in the bones. Hypocalcemia is the common denominator in hyperparathyroidism.

Treatment modalities may vary depending on the cause. Surgery may be indicated to treat primary hyperparathyroidism. It may entail complete or partial removal of the adenoma. Therapy aimed at lowering calcium levels may be instituted prior to surgery or when surgery is not an option. Postoperatively, calcium, phosphate, magnesium, and sodium phosphate replacements may be indicated. Treatment in secondary hyperparathyroidism aims to correct the underlying cause. The adenomas of patients with chronic conditions may not return to normal size even after lower calcium levels have been achieved. In this case, surgery is indicated.

After treatment, patients will need follow-up with evaluation of calcium levels on a regular basis, especially those who were not treated surgically. These patients are prone to fractures, renal stones and, in severe cases, renal damage may be irreversible. Patients with previous history of pulmonary or cardiac disease may also develop complications from postoperative intravenous therapy.

• Consider service connection on a presumptive basis as a chronic condition (38 CFR §3.307; §3.309 (a)).  

• Consider service connection on a presumptive basis as a condition associated with ionizing radiation exposure (38 CFR §3.307; §3.309 (d); §3.311 (b)).