Parathyroid adenoma is a benign tumor that forms in one of the four parathyroid glands, which are small glands located in the neck. These glands produce parathyroid hormone (PTH), which helps regulate calcium levels in the blood. When an adenoma develops, it can lead to excessive production of PTH, resulting in elevated calcium levels, a condition known as hypercalcemia. Symptoms of parathyroid adenoma may include fatigue, weakness, kidney stones, and bone pain. Diagnosis typically involves blood tests to check calcium and PTH levels, along with imaging studies like ultrasound or CT scans to locate the tumor. Treatment often involves surgical removal of the affected gland.