Phimosis is a tightening of the foreskin that normally folds over the penis. This tightening makes it difficult to pull the foreskin over the tip of the penis.
Some males are born with foreskin tightness. This type of phimosis usually gets better on its own during the first few years of life.
Another type of foreskin tightness occurs when the foreskin is irritated, infected, or has scarring. Treatment, such as circumcision, may be needed for this type of phimosis.