The causes of secondary hyperparathyroidism include autoimmune renal tubular damage, chronic renal insufficiency and other endocrine diseases, as follows: 1. autoimmune renal tubular damage: after the renal tubular damage, it can make the active vitamin D deficiency, leading to intestinal calcium absorption disorder and bone mineralization, inducing secondary hyperparathyroidism. 2. Chronic renal insufficiency: when suffering from chronic renal insufficiency, the decrease of renal phosphorus excretion can lead to phosphate retention, and hyperphosphatemia can cause the decrease of blood calcium, which in turn can induce secondary hyperparathyroidism. 3. Other endocrine diseases: Cortisolism caused by any reason may induce secondary hyperparathyroidism. After the appearance of secondary hyperparathyroidism, it is recommended that the patient consult a doctor in a timely manner to clarify the cause of the disease and then carry out targeted treatment.