There is no such thing as kidney atrophy to a few centimeters is considered serious. Once renal atrophy occurs, it means the condition is more serious. Generally speaking, a difference of 1.5 centimeters between the lengths of the two kidneys is considered diagnostic. Kidneys are important excretory organs of the human body, excreting metabolized toxins and urine from the body every day. It also promotes red blood cell production and renin secretion. Renal atrophy is commonly seen in end-stage of many acute and chronic kidney diseases, renal artery stenosis, renal dysplasia and other diseases. If left untreated, it can lead to systemic multi-system damage, and serious complications such as hyperkalemia and heart failure can occur. Targeted treatment is taken according to different causes of renal atrophy. If renal atrophy is caused by renal artery stenosis, renal artery stenting can be given, and renal atrophy may be slowed down; if it is caused by stones in the urinary system, renal atrophy may be relieved if the stones are removed and the obstruction is lifted; and renal dialysis can also be chosen for treatment if renal atrophy progresses to an advanced stage. When patients have renal atrophy, they should go to regular hospitals in time, and choose the appropriate treatment plan according to the severity of renal atrophy under the guidance of doctors.