Ms. Huang, who has a smooth career and a happy family, has been suffering from unexplained fatigue for more than six years and sometimes feels discomfort in her lower back. She has been diagnosed as having lumbar strain or osteoporosis and treated for it several times, but it has not improved. She went to a hospital to have blood tests for parathyroid hormone, and the results were two times higher than the normal value of parathyroid hormone. After further tests, she was diagnosed with primary hyperparathyroidism, which was caused by a parathyroid adenoma. After surgery to remove the parathyroid adenoma, the fatigue and low back discomfort that had plagued Ms. Huang for years disappeared completely. Why is the invisible and intangible parathyroid adenoma not known to people? It turns out that parathyroid glands are small glands located in the neck, behind the thyroid gland and next to the trachea and esophagus, and there are usually four of them in each person. The parathyroid glands secrete parathyroid hormone, which regulates the body’s calcium and phosphorus metabolism. Once a lesion occurs in the parathyroid glands, such as an adenoma, hyperplasia, or, rarely, adenocarcinoma, too much parathyroid hormone is secreted, causing hyperparathyroidism and resulting in a group of clinical syndromes including hypercalcemia, hypercalciuria, hypophosphatemia, and hyperphosphaturia. Patients often present early with non-specific symptoms, such as unexplained weakness, easy fatigue, weight loss and loss of appetite. Primary hyperparathyroidism is a relatively common endocrine disorder that is more common in women, with a male to female ratio of about 1:3. Most patients are postmenopausal women, with onset mostly in the first 10 years after menopause, but can also occur at any age. Clinically, primary hyperparathyroidism should be considered when the following symptoms occur 1. Irritable thirst, excessive drinking and polyuria often occur; recurrent and multiple urinary stones cause renal colic, ureteral spasm, hematuria in the naked eye, and even gravel-like stones discharged in the urine. Patients are also prone to repeated urinary tract infections. 2. Systemic diffuse and gradually increasing skeletal and joint pain, with more prominent bone pain in weight-bearing areas, such as the lower limbs and lumbar spine. Skeletal deformities, such as thoracic collapse, scoliosis, pelvic deformation, and curvature of the limbs, may appear in the longer course of the disease. Patients may have short height. Fractures are easily triggered by minor external forces, or spontaneous fractures may occur. Osteomalacia of unknown cause, especially with subperiosteal bone cortical resorption and/or alveolar bone plate resorption and bone cyst formation, etc. 3. Symptoms such as poor appetite, nausea, vomiting, indigestion and constipation of unknown origin. Some patients may develop recurrent peptic ulcers, manifesting as epigastric pain and black stools. Some patients with hypercalcemia may develop acute or chronic pancreatitis, with clinical manifestations such as epigastric pain, nausea, vomiting, poor appetite and diarrhea, or even with acute pancreatitis attacks. 4. Unexplained psychoneurological symptoms, especially those accompanied by thirst, polyuria and bone pain. Psychological abnormalities such as lethargy, drowsiness, depression, neuroticism, decreased social interaction ability, and even cognitive impairment may appear. 5.Patients with hypercalcemia may develop apathy, depression, irritability, unresponsiveness, memory loss, and even central nervous system symptoms such as hallucinations, mania, and coma in severe cases. Patients are prone to fatigue, muscle weakness and hypertension. Some patients also exhibit muscle pain, muscle atrophy, and weakened tendon reflexes. In conclusion, patients with primary hyperparathyroidism often have different degrees of disease, with varying degrees of clinical manifestations, variable and non-specific, and are easily overlooked by patients and missed by physicians, which should be a cause for concern. Once primary hyperparathyroidism is suspected, parathyroid hormone measurements should be performed. The diagnosis of primary hyperparathyroidism should be considered when hypercalcemia is present with blood parathyroid hormone levels above normal or at levels on the high side of the normal range. Surgery is preferred for the treatment of primary hyperparathyroidism and is very safe and reliable.