Hyperparathyroidism is an endocrine disorder characterized by excessive secretion of parathyroid hormone (PTH) from the parathyroid glands. PTH plays a central role in regulating calcium, phosphate, and vitamin D metabolism. Excess hormone production disrupts this balance, leading to elevated blood calcium levels and widespread systemic effects.

The condition is classified as primary, secondary, or tertiary hyperparathyroidism. Primary hyperparathyroidism is most commonly caused by a benign parathyroid adenoma and results in inappropriate overproduction of PTH. Secondary hyperparathyroidism occurs as a compensatory response to chronic hypocalcemia, often due to vitamin D deficiency or chronic kidney disease. Tertiary hyperparathyroidism develops after prolonged secondary disease, with autonomous hormone secretion.

Clinical manifestations vary and may be subtle in early stages. Symptoms include fatigue, bone pain, muscle weakness, kidney stones, abdominal discomfort, constipation, depression, and cognitive changes. Chronic elevation of calcium leads to bone resorption, increasing the risk of osteoporosis and fractures.

Diagnosis is based on laboratory findings of elevated calcium levels with inappropriately high or normal PTH levels. Additional tests assess vitamin D status, kidney function, and bone density. Imaging studies may be used to localize abnormal parathyroid glands when surgical treatment is considered.

Management depends on the type and severity of disease. Primary hyperparathyroidism may require surgical removal of the affected gland, particularly in symptomatic patients or those with complications. Medical management and monitoring may be appropriate in selected cases.

Secondary hyperparathyroidism is treated by correcting the underlying cause, such as vitamin D deficiency or phosphate imbalance. Long-term monitoring is essential to prevent skeletal and cardiovascular complications.

Early recognition and appropriate treatment restore calcium balance, protect bone health, and prevent long-term organ damage, making hyperparathyroidism a critical condition within endocrine practice.