The pathogenesis of this disease is mainly the following: 1. caused by rheumatic diseases, such as rheumatic kidney disease, if the condition continues to worsen, it may be complicated by rheumatic arthritis, which leads to pain in the lower limbs. 2. caused by renal insufficiency, such as chronic glomerulonephritis, nephrotic syndrome, which is a disease that complicates the excretion of waste products in the body. The kidneys are not the anatomical kidneys, but a functional area. If there is a lesion here, it will often cause a series of symptoms such as weakness in the lower limbs or soreness in the lower back.