The reason for kidney pain after ejaculation is mainly the following: 1. Men have been masturbating or having sex too often for a long time, which leads to a deficiency of kidney energy in the human body. 2. Men suffering from vesiculitis, prostatitis, urethritis and other diseases can lead to painful lumbar tugging after ejaculation. 3. The symptoms of pain in the kidney area after ejaculation can occur due to lumbar muscle strain and lumbar spine small joint disorders. 4. When men suffer from ureteral stones and kidney stones, sexual intercourse can lead to stone activity, stone impaction causing hydronephrosis and ureteral dilatation, and pain in the kidney area after ejaculation. Patients are advised to go to the urology department of a regular hospital in a timely manner to improve relevant examinations and actively carry out treatment under the guidance of a doctor after clarifying the cause.