Swelling? If true swelling is occuring in your penis than that is probably a result of injury. You can get an injury many ways. Priapism is known to cause swelling because of the internal injuries it causes. Infants as well as adults can get an injury in their penis just by having their penis trapped by clothing when a solid erection is occuring. Bending an erection is even more harmful. Many penis enargement tricks or exercises are known to cause injuries. A good rule is if it hurts don't do it and if you have any numbness the area may not be feeling the injury and you could injur unaware.I suggest if you care about preserving the function of your penis you should see a urologist asap.