Cryptorchidism is often accompanied by unclosed sphincter on the affected side, which can be manifested as syringomyelia or inguinal hernia. It is not uncommon for intestinal hernia to become embedded and easily cause intestinal necrosis; it can also compress the blood vessels of spermatic cord, causing further atrophy of cryptorchidism and, in serious cases, testicular infarction. Common complications and associated deformities of cryptorchidism are as follows: 1. Decreased fertility or infertility Cryptorchidism can lead to damage of germ cells, so early surgical treatment should be performed to fix the testes in the scrotum to reduce the risk of decreased fertility. Cryptorchidism has no normal spermatogenic function due to histopathological changes. the higher the position of cryptorchidism and the longer it is above the scrotum, the greater the damage to the testicular varicoceles. by Mengel’s observation with general microscope and electron microscope, cryptorchidism patients have pathological changes of varicoceles and interstitial cells and obvious spermatogenic damage in the testes before the age of 2. Hecker’s examination of normal adults and unilateral Hecker examined the sperm concentration of normal adults and unilateral cryptorchidism patients after testicular fixation, and the former was significantly higher than the latter, indicating that unilateral cryptorchidism patients had bilateral cryptorchidism damage. In untreated bilateral cryptorchidism patients, infertility can reach 100%, and if early treatment is given, fertility can reach 40%. While unilateral cryptorchidism can reach 60% fertility after early treatment. Treatment of patients before the age of 2 years helps to improve the development of spermatogonia and increase the number of spermatogonia and subsequent spermatogenesis. Patients with unilateral and bilateral cryptorchidism have lower than normal spermatogenic capacity in adulthood despite early treatment. The earliest postnatal histological abnormality in cryptorchidism is mesenchymal dysplasia, which can be observed in the first month of life. Unilateral cryptorchidism after puberty should be removed, as it is prone to malignancy and torsion in the future, and the vast majority of testes lose their fertility. The temperature of the scrotum is slightly lower than the body temperature, which is suitable for the development of germ cells in the normal testis. The testis is in the abdominal cavity or inguinal cavity, where the temperature is the same as the body temperature, which is not suitable for the development of germ cells, and thus the testicular tissue structure is also poorly developed. If left untreated, bilateral cryptorchidism often leads to metachronous spermatorrhea, making most patients infertile. One side of cryptorchidism, while the other testicle is normal, can maintain normal or near normal physiological function. If unilateral cryptorchidism is not treated, more than 30% of patients are infertile. Testicular injury Testicles located in the inguinal canal or near the pubic symphysis are superficial and fixed, so they are easily damaged by external force. 3.Cryptorchid testicular torsion The chance of torsion of the undescended testicle is more than 20 times higher than that of the testicle in the scrotum. Cryptorchidism may have abnormal attachment of testicular lead, levator muscle or abnormal attachment of testicular sphincter, which makes it easy for testicular torsion to occur. Although torsion of the undescended testis rarely occurs, testicular torsion should be considered in cases of abdominal pain or groin pain with ipsilateral scrotal emptiness. If there is a normal testicle in the scrotum, cryptorchidism torsion can be excluded. 4. Malignant changes Children born with undescended testicles are at risk of developing testicular malignancy. The incidence of germ cell tumors in men with cryptorchidism is about 18-40 times higher than that in normal people. The location of the undescended testis influences the relative risk of tumor development in the testis; the higher the location, the greater the risk of malignant transformation. Half of the intra-abdominal testes will develop malignant transformation. The age of onset of cryptorchid malignancy tends to be after 30 years of age. testicular fixation before the age of 2 years, and the rate of malignancy occurring afterwards, is much lower than if the procedure was performed at an older age. The most common type of testicular tumor due to cryptorchidism is seminomatous cell tumor. The incidence of carcinoma in situ in patients with cryptorchidism is 1.7%. Early surgery cannot prevent malignant transformation of cryptorchidism, and in patients with unilateral cryptorchidism, the histology of the testis on the opposite side, which has descended to the normal position of the scrotum, is also abnormal, so there is also a high incidence of malignant transformation. In patients with unilateral cryptorchidism, one fifth of the malignant changes are found to occur in the non-cryptorchid testis, while in patients with bilateral cryptorchidism, if malignant changes occur in one testis, 15% of the other testis is found to be malignant. 5.Cryptorchidism with abnormalities Cryptorchidism can be a single disease, but it can also be accompanied by other genitourinary system abnormalities and other endocrine diseases and genetic diseases. It is most common to have vas deferens and epididymal abnormalities. 6.Mental injury Abnormal testicular position often causes low self-esteem in older children.