There are many causes of penile and scrotal edema, and the symptoms of penile and scrotal edema are mostly edema-like, painful and, in severe cases, can lead to unfavorable urination and difficulty walking. Since penile and scrotal edema visually manifests as edema and swelling of the diseased area, and many diseases of the male genital area also produce edema and other phenomena, the diagnosis of penile and scrotal edema needs to be differentiated from the following diseases: 1. Scrotal edema: the scrotum is a loose tissue that is prone to edema, which can be part of systemic edema, or can be caused by local factors, such as local inflammation or allergic reactions, venous blood or lymphatic reflux obstruction; tension ascites can cause significant scrotal swelling; posterior peritoneal hemorrhage (such as ruptured abdominal aortic aneurysm) appears as non-traumatic penile scrotal petechiae, also known as Bryant blue genital sign. 2, scrotal elephantiasis: scrotal swelling, rough skin, thickening like elephantiasis. It is often due to lymphangitis or lymphatic vessel obstruction caused by hemosiderosis, and lymphogranuloma of venereal disease caused by Chlamydia, and scrotal elephantiasis can also appear in late stages. 3. Scrotal hernia: Scrotal hernia is an inguinal hernia in which intra-abdominal organs such as intestinal canal or mesentery descend into the scrotum through the inguinal canal. It is characterized by enlargement of the scrotum on one side or both sides and a cyst-like sensation when touched. Sometimes it can be pushed back into the abdominal cavity in the supine position or by hand, but it can descend into the scrotum again when the intra-abdominal pressure is increased by coughing or other reasons. 4.Syringomyelia: If the scrotum is swollen and painless to touch, with a cyst-like sensation, and always located in front of the testicles, it is mostly testicular syringomyelia.