Renal insufficiency is a disease with multiple causes including acute and chronic renal decompensation, pathologic injury, abnormal blood or urine composition, and abnormal imaging studies. Renal insufficiency includes acute kidney injury, acute tubular necrosis, and chronic renal failure. The etiology of acute kidney injury includes, according to the anatomical site, pre-renal damage: reduced blood volume (e.g. shock haemorrhage, heart failure, cirrhosis pumping ascites); renal damage (drug toxins – gentamicin, depot tablets, contrast agents, aminoglycosides, etc. leading to tubular necrosis); post-renal damage (urinary tract obstruction – stones, tumors, etc.); the main etiology of acute tubular necrosis is the use of nephrotoxic agents, including exogenous toxins (biotoxins, chemical toxins, antibacterial drugs contrast agents, etc.) and endogenous toxins (hemoglobin, myoglobin); can occur on the basis of a variety of predisposing factors such as old age, diabetes mellitus, and the involvement of ischemic factors; the main cause of chronic renal failure is mainly primary glomerulonephritis in China and diabetic nephropathy in foreign countries. Treatment of renal insufficiency should correct the etiology, and for various severe trauma, heart failure, acute blood loss should be related treatment including blood transfusion, isotonic saline expansion, treatment of blood volume deficiency, shock and infection; also maintain fluid balance and pay attention to supplemental nutrition, and dialysis treatment should be performed when end-stage renal failure occurs.