Whether hyperparathyroidism is serious or not depends on the cause of the disease. It is less serious if it is a parathyroid adenoma with a good prognosis after surgical treatment. 1. Parathyroid adenoma: Hyperparathyroidism in this case is relatively less serious, patients will show chronic hypercalcemia as well as symptoms such as thirst, insomnia, and poor appetite, etc. Surgical treatment to remove the adenoma generally has a good prognosis. 2. Thyroid cancer: the hyperparathyroidism in this case is more serious. Thyroid cancer will lead to a large amount of secretion of parathyroid hormone, resulting in hyperparathyroidism and affecting the calcium and phosphorus metabolism, which will show serious hypercalcemia and may even be life-threatening. Patients diagnosed with hyperparathyroidism should consult the doctor in time and be treated under the doctor’s guidance.