Hygiene, in particular the regular cleaning of the glans, is generally considered sufficient to prevent infection and inflammation of the foreskin. Full retraction of the foreskin may not be possible in boys younger than about ten years and some may not be able to fully retract their foreskin for cleaning until their late teens.

Posthitis can have infectious causes such as bacteria or fungi, or non-infectious causes such as contact dermatitis or psoriasis. The inflammation may be caused by irritants in the environment. Common causative organisms include candida, chlamydia, and gonorrhea. The cause must be properly diagnosed before a treatment can be prescribed. A common risk factor is diabetes.

Posthitis can lead to phimosis, the tightening of the foreskin which makes it difficult to retract over the glans. Posthitis can also lead to superficial ulcerations and diseases of the inguinal lymph nodes.