Congenital isolated kidney means that there is only one kidney. Normal people have two kidneys, one on each side. The incidence of congenital isolated kidney is relatively high, according to statistics, about 1/1500, why normal people do not encounter so many? Because many people do not go to physical examination and do not find out, do not find out they have only one kidney, is sick or hospital for examination, only to find out isolated kidney. Isolated kidney is often combined with ipsilateral ureteral atresia, the incidence is higher in men than in women, and it is more common on the left side, often accompanied by malformation of male and female reproductive organs, such as ipsilateral epididymal tail, ejaculatory duct, vas deferens and ipsilateral testicular absence in boys; girls show ipsilateral ureteral absence, unicornuate uterus or bicornuate uterus.