The presence of blood vessels on the penis is a manifestation of the appearance of the penis, which needs to be judged in conjunction with the clinical history and symptoms, and the causes of the corresponding conditions mainly include physiological factors, varicose veins, sclerosing lymphadenitis, etc. The symptoms are mainly due to the presence of blood vessels on the penis, which are usually the superficial dorsal veins of the penis. 1. Physiological factors: most people will have blood vessels visible when the penis is erected, usually the superficial dorsal penile veins, which mainly play the role of draining blood from the scrotum and penis. 2. Varicose veins: some people may have varicose veins on the surface of the penis due to the increase of venous pressure, which is related to the abnormalities of valve anatomy and function. 3. Sclerosing lymphangitis: the corresponding lesion is not a blood vessel, but a tortuous dilated lymphatic vessel, purplish in color, hard texture, no adhesion with the surrounding tissues, and some patients will be accompanied by pain. The appearance of blood vessels on the penis, accompanied by obvious other discomfort, need to consult a doctor in a timely manner, after diagnosis of the cause of the disease in the clinician’s guidance for standardized treatment, to avoid delays in the condition.