Phimosis is a painful condition that makes it difficult to retract the foreskin of the penis. It occurs in boys and men who have not undergone circumcision (removal of the foreskin covering the tip of the penis). Tissue damage can occur if the foreskin is forcibly retracted. Phimosis is common in newborn males because the skin covering the tip of the penis is still tight and less pliable, and it is fairly normal for most babies and toddlers to have initial difficulties with retracting the foreskin. Phimosis typically resolves or improves on its own with age. Most boys can retract their foreskin completely by the age of three.

Another condition affecting the foreskin is called paraphimosis, in which repositioning of the foreskin to the unretracted position is not possible, and this limits or stops blood flow to the penis. It is a more serious condition because it affects blood supply and must be treated in an emergency setting.