Penile venous fistula can be caused by injury to the corpus cavernosum, penile disease, and testosterone deficiency. 1. Injury to the corpus cavernosum of the penis: Penile venous fistula may occur because of trauma to the corpus cavernosum and abnormal venous return. When the penis is engorged with blood, there is a lot of blood in the glans area. 2. Penile congenital disease: penile venous fistula may also be the presence of congenital diseases in the penile area, congenital developmental abnormalities may also lead to the appearance of penile spongy fistula. 3. Testosterone deficiency: testosterone is an androgen. If the level of testosterone in a man’s body is low, it will affect the development of penile veins and cause penile venous fistula. If penile venous fistula occurs, it is recommended to go to the hospital in a timely manner, under the guidance of the doctor for a comprehensive and systematic examination, to clarify the cause and then targeted treatment.