A man with only one kidney will not have abnormal kidney function because only 10% of the kidneys are functioning and 90% of the kidney cells are resting in rotation. Kidney transplant patients have completely normal kidney function even if they donate one kidney or transplant one kidney successfully. However, it is recommended that patients with only one kidney should pay attention to rest and avoid overexertion, and should protect the residual kidney well, especially avoid any operation on the kidney, such as renal puncture is not recommended, nor surgical treatment, and avoid the application of nephrotoxic drugs. It is recommended to have a low salt, high quality, low protein diet, and at the same time should be checked every 3-6 months for blood routine, urine routine, ion, renal function, etc. If there is any disease, early treatment is recommended to prevent irreversible consequences caused by delay.