The foreskin has protective, sensory, biomechanical, and immunological functions. Throughout life, the outer part of the foreskin protects the sensitive inner part of the glans from injury, abrasion, chafing, and infection. The foreskin keeps its mucosal tissue and the glans soft and moist so that it maintains sensitivity.
The foreskin also secretes immunological substances that fight infection, called lysozymes, and also produces natural lubricants, reducing the need for artificial lubricants during sex.
In men, circumcision is sometimes considered a treatment option for the following conditions:
Tight foreskin (phimosis) – where the foreskin is too tight to be pulled back over the head of the penis (glans); this can sometimes cause pain when the penis is erect and, in rare cases, passing urine may be difficult
Recurrent balanitis – where the foreskin and head of the penis become inflamed and infected
Paraphimosis – where the foreskin can't be returned to its original position after being pulled back, causing the head of the penis to become swollen and painful; immediate treatment is needed to avoid serious complications, such as restricted blood flow to the penis
Balanitis xerotica obliterans – a condition that causes phimosis and, in some cases, also affects the head of the penis, which can become scarred and inflamed
Cancer of the penis – a very rare type of cancer that can occur in men, where a red patch, wart-like growth or ulcer appears on the end of the penis or under the foreskin
In most cases, circumcision will only be recommended when other, less invasive and less risky treatments have been tried and haven't worked