Suggest Remedy For Non Retractablility Of Foreskin When Erect

Hello doctor i am male ,21 and i am from india, i have penis forskin problem.When penis is in normal condition then skin is easy remove from top but when penis gone a excited then skin does not remove and when i try to do then it s very pain full moment .So what u suggest doctor? Plz help me.is it cause any serious problem??