The Foreskin: Anatomy and Function

This page presents information about the foreskin, the tissue removed by circumcision. With an understanding of the structure, functions, and purpose of the foreskin we can understand the impact of male circumcision on human sexuality.

Functions of the Foreskin

  • Protection: The foreskin covers and protects the glans and urinary opening from abrasion, irritation, and foreign material.
  • Pleasure: The foreskin is the most sexually sensitive and pleasurable part of the penis. Because most adult men in America were circumcised at birth, there is a common misconception that the glans is the most pleasurable part of the penis. A specialized ridged band of tissue encircling the tip of the inner foreskin contains thousands of erogenous nerve endings which provide intact men with the majority of their sexual sensation, making the foreskin vital to the male sexual response. Circumcision removes this highly erogenous tissue, resulting in a dramatic reduction in sexual sensation.
  • Sexual: During intercourse, the intact penis glides back and forth inside its skin sheath, greatly reducing the friction between the penis and vaginal walls. Because of this, women report improved sensation and comfort with an intact penis. For more information see Dr. Christiane Northrup's article How Male Circumcision May Be Affecting Your Love Life.
  • Structural: The foreskin provides sufficient skin length to accommodate penis growth and allows for comfortable erections.

Foreskin Anatomy

Foreskin Retraction Process

The foreskin, or prepuce, is a retractable, double-sided fold of skin and mucosal tissue that covers the glans, or head, of the penis. The foreskin is an integral and significant part of the overall penile skin system, and in the adult male the foreskin is 15 square inches in size. The outside of the foreskin is like the skin on the shaft of the penis but the inner foreskin is mucosal membrane like the inside of the eyelid or the mouth. The foreskin contains blood vessels, nerve endings, and a thin layer of muscle.

The penile skin (including the foreskin) is free to move over the penile shaft because the double-sided nature of the foreskin makes the penile skin system considerably longer than the penile shaft and also because the penile skin is only connected to the underlying structures at the pelvis and at the base of the glans (at the sulcus). This ability to move is the hallmark physical characteristic of the penile skin system (see this animated diagram) and it plays a vital role in intercourse.

Note: the ridged band is not shown in the above diagram. See this detailed cross section of the intact penis for more information.

Additional reading on foreskin anatomy:
    CIRP: Anatomical diagrams of intact and circumcised anatomy
    Wikipedia page on the foreskin (Adult Content)

Foreskin's Role as Sensory and Erogenous Tissue

As demonstrated by the recent fine touch study and a previous anatomical study, the foreskin is a highly tuned sensory organ with thousands of specialized nerve endings. In fact, the foreskin has more nerve endings than any other part of the penis. The foreskin's ability to detect touch, motion, vibration, temperature variations, texture, and moisture is unmatched in male sexual anatomy.

The density and specialization of the foreskin's nerve endings are similar to that found in the lips. To demonstrate the significance of high concentrations of nerve endings, gently run your fingertip across your cheek or chin. Then gently run your fingertip across your lips. The intense, detailed sensation you feel when touching your lips shows how much sensation your lips provide. Imagine how it would feel to eat food or kiss a lover without the sensations provided by the lips. This will give you some idea of the amount of sensation contained in the foreskin and lost to circumcision.

The largest concentration of nerve endings in the foreskin are in the frenulum and the tip of the foreskin. The frenulum is the Y-shaped connective tissue on the underside of the penis just behind the glans. The frenulum tethers the foreskin to the glans, in much the same way the tongue is tethered to the bottom of the mouth. The frenulum is highly erogenous and very pleasurable to the touch. Often, circumcision doesn't remove all of the frenulum; this is why many circumcised men enjoy being touched in that area. Imagine how much better it would feel for them if their frenulum was whole!

The ridged band is an area of highly erogenous tissue in the inner foreskin. It radiates out from the frenulum and encircles the penis, about 1/2 inch from the junction between the inner and outer foreskin. This cross section shows the location of the ridged band. Unfortunately, circumcision almost always removes the entire ridged band and with it, the erogenous sensations it provides.

The foreskin gives a man a tremendous amount of pleasure as well as detailed information about his sexual response. While the foreskin has fine-touch receptors, the glans, in contrast, has pressure receptors and lacks the fine-touch receptors found in the foreskin. This is why the sensations provided by the foreskin are so different from the sensations provided by the glans. It is the combination of these two sensations that provide intact (uncircumcised) men with the full range of sexual feeling.

Functions of Foreskin (Prepuce)

The Foreskin: 15 Square Inches of Erogenous Tissue

Foreskin Development

At birth and for the first few years of a male's life, the inside fold of the foreskin is attached or fused to the glans, in very much the way the eyelids of a newborn kitten are sealed closed. The tissue that connects these two surfaces dissolves naturally over time - a process that should never be hurried. Premature or forcible retraction can tear the foreskin from the glans causing pain, bleeding, infection, and even skin adhesions.

The first person to retract a child's foreskin should be the child himself and no one else.

The foreskin can be retracted when its inside fold separates from the glans and its opening widens. This usually happens by age 18. Even if the glans and foreskin separate by themselves in infancy, the foreskin may not yet be retractable because the opening of a baby's foreskin may be only large enough to allow for the passage of urine. As the genitals develop, the opening of the foreskin increases in size to allow the foreskin to retract.

The age at which the foreskin becomes retractable is highly variable from one individual to another. Some boys have retractable foreskins by the age of 2, while others are not retractable until the age of 18. One flawed study said that the foreskin should be retractable in all boys by the age of 5; this is not true. Each boy develops differently and there is no set age at which the foreskin must be retractable.

Normal development of the prepuce: Birth through age 18

For detailed technical information on the development of the foreskin (both in utero and from infancy to maturity), see The Anatomy and Physiology of the Human Prepuce.

Care of the Foreskin

A boy's intact penis needs very little care. The best advice is to simply leave it alone. Before the foreskin is retractable, cleaning under it is not needed. Simply wash the outside of the penis during normal bathing. Once the foreskin is retractable, cleaning the intact penis is easy and can be remembered by the three Rs: Retract the foreskin, Rinse with warm water, and Replace the foreskin back over the glans. Generally, soap is not recommended for the inner foreskin because soap can cause irritation and disrupt the natural balance of beneficial bacteria. Rinsing with clean warm water is normally sufficient. If you have any questions, please contact us.

Additional information about care of the intact (uncircumcised) penis:
         CIRP: Penile hygiene for intact (non-circumcised) males
         American Academy of Pediatrics: Care of the Uncircumcised Penis
         NOCIRC: Answers To Your Questions About Your Young Son's Intact Penis


Contrary to the uniquely American belief that the foreskin is prone to infection, most intact males live their entire lives without ever having a problem with their foreskin. When the occasional infection does occur, it can usually be treated with antibiotics.

The vast majority of infections of the foreskin are caused by premature or forcible retraction of a child's foreskin that has not yet separated from the glans. Premature or forcible retraction can tear the bond between the foreskin and glans causing bleeding and creating an opening for bacterial infection. All too often a doctor, baby sitter, or parent mistakenly believes that the foreskin must be retracted or cleaned in a young boy and the subsequent tearing and bleeding allows for an infection, which then leads to a conclusion that circumcision is required (or should have been done at birth). If the foreskin had just been left alone, there wouldn't have been a problem in the first place.

Ballooning during urination

As a boy's foreskin begins to separate from the glans (and if the foreskin's opening is still small) his foreskin may expand (balloon) during urination. This is caused by the pressure of the urine, and is no cause for alarm. Ballooning will not cause an infection. As the genitals develop and the foreskin's opening increases in size, the ballooning will subside.


Phimosis is a condition where the foreskin cannot retract. A valid diagnosis of phimosis is possible only in adult males. Because the foreskin is fused to the glans at birth and slowly separates over time, a non-retractable foreskin is a normal condition in children. Remember that two conditions must exist for the foreskin to become retractable: 1) the glans and foreskin must have separated and 2) the foreskin opening must have increased in size so it can stretch over the glans. Both of these happen over time as a boy matures, and each boy develops at a different rate. Some boys' foreskins are retractable at the age of 2; others aren't until the age of 18 - these variations are normal. A child's foreskin should never be forcibly retracted. The first person to retract a child's foreskin should be the child himself and no one else.

The vast majority of phimosis cases can be effectively treated without resorting to amputation of the foreskin (circumcision). The goal should be to help the foreskin become retractable, not to amputate it. Conservative treatment options include manual stretching, topical medications, and conservative surgical procedures to loosen the opening of the foreskin.

Conservative Treatment of Phimosis: Alternatives to Radical Circumcision


Paraphimosis is a condition where the foreskin has been retracted and becomes trapped behind the head of the penis. This interferes with blood circulation in the penis and the result is edema, which is what causes the swelling. There is normally no reason to believe that infection is present. It is sometimes described as looking like an inner tube is circling the penis right behind the glans or head of the penis. Paraphimosis is a medical emergency because circulation is impaired. The emergency is over when the foreskin is brought forward to its normal position.

The proper first aid is to squeeze the head of the penis between thumb and fore finger to force the blood out of the head so as to reduce its size at which time the foreskin may be brought forward. Circumcision is not needed, but doctors unfamiliar with proper treatment for paraphimosis may erroneously suggest it.

For more information: Paraphimosis: Conservative Treatment.

Urinary Tract Infections (UTIs)

Urinary tract infections (UTIs) are bacterial infections of the urinary tract (kidneys, ureters, bladder and urethra) and are usually associated with congenital abnormalities of the urinary tract. Most UTIs can be treated with antibiotics. Some have advocated circumcision as a way to treat recurrent UTIs, but there is no medical evidence to support the idea that the foreskin causes them. For a discussion about UTIs and circumcision, see: CIRP: Circumcision and urinary tract infection.


Balanitis is an inflammation of the glans (not necessarily an infection) and can occur in both circumcised and intact males. For information about balanitis including treatment, see: CIRP: Balanitis.

Balanitis Xerotica Obliterans (BXO)

Balanitis Xerotica Obliterans is a rare but relatively serious disease. From CIRP: "BXO is usually distinguished by a ring of hardened tissue with a whitish color at the tip of the foreskin. The hardening of the tissue prevents retraction of the foreskin." For more information about BXO including treatment, see: CIRP: Balanitis Xerotica Obliterans.