Phimosis (fy-MOH-sis) is a tightness of the foreskin in uncircumcised males that prevents the foreskin from retracting over the head of the penis.
Boys are born with a hood of skin, called the foreskin, covering the head (also called the glans) of the penis. Some boys have the foreskin removed through a procedure called circumcision, but many boys don't.
In uncircumcised babies, the foreskin starts off stuck to the glans, and it can't be pulled back. This is known as physiologic phimosis, and it is a perfectly normal condition. Over time, the foreskin gradually loosens, and most boys are able to retract it after about the age of 5.
In older boys and adults, phimosis can be caused by an injury to the foreskin — often due to the foreskin being forcibly retracted before it's ready — or by a bacterial infection of the foreskin or glans. This is called pathologic phimosis, and it can lead to recurring infections, problems while urinating (peeing), and pain during sexual intercourse.
In most cases, physiologic phimosis will clear up on its own within the first few years of life, although some cases may last until a boy is in his teens.
Cases of pathologic phimosis that cause pain, infection, or problems with peeing might be treated with topical medicine (medicine applied to the skin) or surgery.
All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts.
