In men, the foreskin (lat. praeputium) refers to the skin surrounding the glans of the penis. It can be pulled back behind the glans during an erection.
The primary function of the foreskin is to keep the glans of the penis moist and tender. It also protects the glans from injury (e.g. from friction) and from drying out. However, the foreskin is also a reservoir for fungi and germs, which can lead to illnesses if hygiene is inadequate.
Many men therefore still opt for circumcision in adulthood. Although this reduces the likelihood of diseases of the glans penis caused by infections, it also leads to reduced sensitivity of the glans tissue due to the long-term drying out of the glans.
One of the most common diseases of the foreskin is phimosis - a painful constriction that permanently prevents the foreskin from retracting. Today, however, this can be easily treated surgically.
Posthitis (inflammation of the foreskin) is often a side effect of a narrowing of the foreskin, as this can also lead to a decrease in hygiene. Such inflammations must be treated immediately with suitable ointments and medication in order to avoid long-term damage.