Phimosis is a condition where the end of the foreskin is so tight that the foreskin can't be pulled back to expose the head of the penis. It is a natural condition in newborn males.

Almost all males are born with a foreskin that can't be retracted. Circumcision removes the foreskin. But in males that aren't circumcised, this type of phimosis usually goes away on its own during childhood.

Another type of phimosis can occur when an infection or inflammation causes scarring. Treatment, such as circumcision, may be needed for this type of phimosis.