Common penile redness and swelling are mainly penile injury, inflammation, malignant tumors and several other causes: 1, penile trauma, mostly seen after violent masturbation, repeatedly rubbing the penis, will lead to local redness and pain in the penis, you need to quit masturbation habits, local symptoms can slowly recover, in addition, if the underwear is tight, the daily penis receives squeezing stimulation, will also lead to penile redness and swelling, you can consider replacing the cotton underwear. Appropriate loose some, also can reduce the local squeeze stimulation. 2, acute inflammation of the penis, such as circumcision, glansitis and other conditions, mostly seen in circumcised or circumcised patients, due to the circumcision of the glans, daily personal hygiene cleaning is not timely, easy to stimulate the glans, resulting in local inflammation of the situation, the glans and foreskin and redness and pain, may find some small herpes, may be accompanied by local itching, need to pay attention to personal hygiene, if necessary, you can go to If necessary, you can go to a public hospital urology department to check and see, you may need to do circumcision. 3, venereal disease, if you have unclean sex before, there may be infections of venereal disease, such as gonococcal infection or non-gonococcal infection, etc., can also be manifested as local redness and swelling, while may be accompanied by urethral discharge. 4, malignant lesions, malignant tumors of the genitalia are relatively rare, if the penis appears red and swollen, at the same time appear cauliflower-like things, we should consider whether there are malignant lesions, it is recommended to promptly seek medical examination. You can look at it yourself against the above and seek medical attention in time to avoid delaying the condition and delaying treatment.