Clinical common reversible factors: (1) infections: respiratory tract and urinary tract infection is the most common. (2) urinary tract obstruction: urinary tract stones, BPH is the most common. (3) blood pressure: This is the most common chronic renal failure symptoms, but sustained high blood pressure will affect kidney function. Antihypertensive treatment can be different levels to improve kidney function. (4) inappropriate use of renal toxicity of drugs: such as sugar-type antibiotics, non-steroid anti-inflammatory drugs, such as sexual. (5) cells, fluid loss: If nausea and vomiting, diarrhea, excessive and inappropriate, such as inadequate water intake. (6) improper diet: If excessive consumption of protein. (7) overworked. (8) electrolyte imbalance: as low calcium, low potassium or high-K. (9) primary disease: such as lupus nephritis after proper treatment, kidney function can be improved or reversed. (10) drug allergy.