there are two chambers in the shaft of the penis called the corpus cavernosa. when blood engorges the corpus it should equally fill but in some cases one side gets more blood than the other causing a deviation. in severe cases where one side of the corpus does not engorge at all this is called peyronie's disease. the blood supply may be due to a plaque or blockage. this is not caused by tight underwear. as a matter of fact tight underwear should have no adverse effect on the angle of your erection whatsoever. since you cannot be adequately diagnosed over the internet and since this change is concerning you you will need to see a urologist (find a male urologist) to be properly evaluated.
what are all the treatment options for straightening a penis that has been bent in an angle due to tight underwear? . 19 year old. had a perfectly natural straight penis with an upward curve (like a perfect banana) in childhood up until puberty. used to wear tight underwear and slept in a certain way (putting penis in between legs) with erection until morning. penis no longer curves upwards but now curves downwards and to the right. when i'm excited penis gets very hard especially glans and the shaft turns into an hourglass figure which feels good & goes away after full erection. penis doesn't hurt at all