All factors that cause permanent damage to kidney function can cause uremia. The first one is immunodeficiency, the most common one is chronic nephritis, immune, glomerular or vascular, and another one is lupus erythematosus nephritis, allergic purpura nephritis, mainly because of abnormal immune presence. Secondly, there are some clear congenital diseases, such as congenital polycystic kidney, and vascular diseases that cause problems with the vascular supply of the kidney. The third, metabolic diseases, such as severe diabetes mellitus, severe hypertension cause kidney function damage. Fourthly, the problem of drug poisoning in daily life, some drugs can cause permanent damage to kidney function when taken for a long time or in large doses. The fifth one is the accident in life, such as pyrexia and crush syndrome, which can also cause permanent damage to kidney function and cause uremia.