1, calcium and phosphorus metabolism disorder: early renal insufficiency blood phosphorus filtration disorder, urinary phosphorus excretion decreased, blood phosphorus retention, blood calcium decreased, causing parathyroid hyperplasia, parathyroid hormone (PTH) secretion increased, acting on the bone release Ca2+ to restore blood calcium levels. When renal insufficiency further develops, high blood phosphorus and low blood calcium persist, PTH is also secreted in large quantities, which continues to mobilize bone calcium release, and so on in a vicious cycle, finally leading to fibrous osteitis. 2, vitamin D metabolic disorders: renal insufficiency in the kidney active vitamin D (l, 25 (OH) 2D3) synthesis is reduced. 1, 25 (OH) 2D3 has to promote bone salt deposition and intestinal calcium absorption, synthesis is reduced resulting in bone salt deposition disorders cause osteochondrosis, while intestinal calcium absorption is reduced, blood calcium is reduced, then promote secondary hyperparathyroidism and cause fibrous osteitis. 3, hyperparathyroidism: renal insufficiency secondary to hyperparathyroidism, in addition to causing the aforementioned bone disease, also caused a series of extra-bone lesions. 4, metabolic acidosis: In acidosis, it may affect bone salt dissolution, and acidosis also interferes with the synthesis of 1,25(OH)2D3, intestinal calcium absorption and bone resistance to PTH.