A slight bulge and vague pain on the left side of the male genitals to the base of the thighs may be due to varicocele, hernia, lymphadenitis and other causes. 1. Varicose veins: mainly due to various reasons caused by the abnormal expansion of local veins, stretching and tortuous, may also cause the left side of the male genitals to the root of the thighs have a slight bulge and vague pain. 2. Hernia: left inguinal hernia, may cause the genital area has protruding, as well as the symptoms of hidden pain, may lead to the male genital left to the root of the thigh has a slight bulge and hidden pain. 3. Lymphadenitis: Inguinal lymphadenitis, caused by various reasons, can cause swollen and painful lymph nodes, which can also lead to a slight bulge and vague pain from the left side of the male genitals to the root of the thigh. There may be other reasons for the swelling and pain in the left side of the male genitals to the root of the thigh, so it is recommended to go to the hospital in time for examination and treatment according to the doctor’s advice.