Why Do People Do Circumcision?

People circumcise for a mix of reasons that range from ancient religious obligation to modern public health strategy, with parental habit and medical necessity filling in between. Roughly a third of males worldwide are circumcised, though rates vary enormously by country and community.

Religious Tradition Is the Oldest and Most Common Driver

For most of human history, circumcision has been a religious act. In Judaism, circumcision on the eighth day of life marks a boy’s entry into the covenant between God and the Israelites, with rabbinic tradition treating the blood of circumcision as the seal of that bond. In Islam, circumcision is understood differently: it is framed as a practice necessary for bodily cleanliness rather than a covenantal marker, though it remains a deeply embedded norm. A boy born into either tradition is expected to be circumcised not because his parents weighed pros and cons, but because the practice is woven into what it means to belong to that community.¹ Together, Jewish and Muslim populations account for a large share of circumcised males globally.

In many parts of sub-Saharan Africa and the Pacific Islands, circumcision has nothing to do with Abrahamic religion. It serves as a rite of passage into adulthood, often performed during adolescence as part of initiation ceremonies that mark the transition from boyhood.² In these settings the procedure carries social weight: an uncircumcised man may be excluded from adult responsibilities and marriage eligibility. The reasons are cultural rather than medical, and they predate any knowledge of infectious disease prevention by centuries.

How Common Is It Around the World

Global estimates put male circumcision prevalence at roughly 37 to 39 percent. But that average hides enormous variation. In 63 countries, more than 90 percent of adult males are circumcised, while in the majority of countries the rate falls below the global average.³ The United States is an outlier among Western nations: most boys there are still circumcised soon after birth, while rates in the United Kingdom and much of Europe have dropped sharply over the past half-century. In countries where neither Islam, Judaism, nor a circumcising cultural tradition dominates, rates tend to be low unless a public health campaign (as in parts of East and Southern Africa) has pushed them upward.

What drives a country’s rate often comes down to which of the motivations discussed here holds the most sway. In the Middle East and North Africa, religion is the primary factor. In the U.S., a combination of medical opinion, parental custom, and institutional momentum keeps rates high. In sub-Saharan Africa, traditional rites and, more recently, HIV-prevention programs both contribute.

HIV Prevention Changed the Medical Conversation

The strongest purely medical argument for circumcision emerged from three large randomized trials conducted in South Africa, Kenya, and Uganda during the mid-2000s. Each trial independently found that circumcision cut men’s risk of acquiring HIV through heterosexual sex by roughly half to 60 percent. In the Kenyan trial, HIV incidence over two years was about 2 percent in circumcised men versus about 4 percent in the control group, translating to a risk reduction of around 53 to 60 percent after adjusting for men who did not follow through with their assigned group.⁴ The Ugandan trial found a comparable effect, with as-treated efficacy reaching about 60 percent.⁵

These results led the World Health Organization and UNAIDS to recommend voluntary medical male circumcision as part of a comprehensive HIV-prevention strategy in high-prevalence settings, particularly in Eastern and Southern Africa. Since then, millions of men and adolescent boys have been circumcised through public health programs.⁶ The protection is partial, not total, and it applies specifically to female-to-male vaginal transmission. Circumcision does not replace condoms or pre-exposure prophylaxis, but it adds a durable layer of risk reduction that requires no ongoing adherence.

Protection Against Other Sexually Transmitted Infections

HIV was the headline, but the data extend to several other infections. In the Ugandan trial, circumcised men also showed lower rates of herpes simplex virus type 2 (HSV-2) and high-risk strains of human papillomavirus (HPV). At two years, HSV-2 seroconversion was about 8 percent in circumcised men versus 10 percent in the control group, and high-risk HPV prevalence was 18 percent versus 28 percent.⁷ A Kenyan trial focused on HPV specifically found that circumcised men acquired new HPV infections at about 60 percent the rate of uncircumcised men.⁸

Updated reviews have estimated that circumcision lowers the risk of acquiring HPV and HSV-2 by about 30 percent over time, on top of the roughly 50 to 60 percent reduction in HIV risk.⁹ For syphilis, the picture is less clear: no consistent protective effect has been demonstrated. These findings matter most in settings where STI prevalence is high and access to other prevention tools is limited, but they also contribute to medical organizations’ assessments of circumcision’s net health impact in lower-prevalence countries.

Why Removing the Foreskin Changes Infection Risk

The foreskin is not just a flap of skin. The moist space underneath it, called the subpreputial space, harbors a distinct microbial community. Studies comparing the penile microbiome before and after circumcision have found that removing the foreskin significantly shifts the bacterial landscape. Anaerobic bacteria, the kind that thrive in low-oxygen environments, drop substantially. One study found that total bacterial load and the prevalence of 12 specific anaerobic taxa decreased significantly within a year of circumcision.¹⁰ Another found that circumcision reduced anaerobe abundance on the coronal sulcus by roughly 60-fold.¹¹

Several of these anaerobes, including species of Prevotella and Peptoniphilus, are the same bacteria linked to bacterial vaginosis in female partners. Researchers believe these organisms trigger local inflammation and activate immune cells in the foreskin’s inner lining, which paradoxically makes HIV transmission easier by drawing the virus’s target cells closer to the surface.¹² Removing the foreskin eliminates the warm, moist environment those bacteria need, dries out the tissue, and reduces the density of vulnerable immune cells. The microbiome story helps explain not just the HIV findings but also why circumcision lowers the risk of HPV and HSV-2: fewer pro-inflammatory bacteria means less mucosal disruption for any pathogen to exploit.

Cancer Risk Reduction

Penile cancer is rare in circumcised men. The disease occurs almost exclusively in those with an intact foreskin, and circumcision early in life appears to be strongly protective.¹³ The mechanism runs through HPV: chronic infection with high-risk HPV strains is the leading cause of penile cancer, and circumcision reduces HPV carriage, as the STI data above show. Penile inflammation (balanitis), which is far more common in uncircumcised men, also raises penile cancer risk; meta-analyses have found that balanitis carries about a fourfold increase in risk.¹⁴

The cancer connection extends to female partners. Because circumcised men carry less penile HPV, their partners are exposed to less of the virus. A multinational study found that among women whose male partners had many sexual partners, those with circumcised partners had markedly lower cervical cancer risk.¹⁵ A recent systematic review and meta-analysis confirmed the association: male circumcision was linked to about 35 percent lower odds of cervical cancer in female partners overall, with similar reductions for cervical dysplasia and carcinoma in situ.¹⁶ Cervical cancer is far more common globally than penile cancer, so this indirect protective effect is arguably the more consequential finding in public health terms.

Medical Conditions That Require or Prompt Circumcision

Not every circumcision is preventive. Some are performed to treat conditions that have already developed. Phimosis, a condition where the foreskin is too tight to retract fully over the glans, is the most common medical indication. In boys, a non-retractable foreskin is normal and usually resolves on its own, but when it persists into later childhood or adulthood and causes pain, difficulty urinating, or recurrent infections, circumcision is often the definitive treatment. Paraphimosis, in which a retracted foreskin gets stuck behind the glans and swells, is a more urgent scenario that sometimes ends in circumcision after other interventions fail.

Balanitis, or inflammation of the glans, is another condition that leads to circumcision. It is especially common in men with diabetes or compromised immune systems, where the warm, moist subpreputial environment encourages fungal and bacterial overgrowth. Topical treatments can manage individual episodes, but recurrent balanitis often leads a physician to recommend circumcision as the only lasting fix.¹⁴ Meta-analyses have found that circumcised males have about 68 percent lower prevalence of balanitis than uncircumcised males.¹⁴

Urinary Tract Infections in Infant Boys

One of the earliest medical arguments for neonatal circumcision involved urinary tract infections. UTIs in the first year of life are considerably more common in uncircumcised boys. A systematic review of randomized trials and observational studies found that circumcision was associated with an 87 percent reduction in UTI risk.¹⁷ That sounds dramatic, but context matters. UTIs in boys are uncommon to begin with: most estimates put the baseline risk at around 1 to 2 percent in uncircumcised boys during the first year. An 87 percent reduction on a small baseline means you would need to circumcise many boys to prevent one UTI. This is part of why UTI prevention alone has not been considered a strong enough reason to recommend routine circumcision in most medical guidelines, though it does tip the overall risk-benefit analysis when considered alongside the other health effects.

How Parents Actually Decide

In countries where circumcision is optional rather than culturally mandated, the decision falls to parents, and their reasoning is often more social than medical. Surveys consistently find that the strongest predictors of circumcision are the father’s own circumcision status and the influence of family and friends. In one study, a factor analysis revealed a cluster of beliefs that travel together: parents who thought circumcision’s benefits outweighed the risks also tended to believe that fathers should look like their sons, that circumcised penises look better, that the procedure helps with cleanliness, and that it is not too painful for infants.¹⁸ In other words, these are not separate independent judgments but one bundled cultural attitude.

Another survey found that the final decision rested with the mother in about half of cases, and the most commonly cited reason for choosing circumcision was medical or hygienic rather than religious. Physicians were the top information source, followed closely by friends and family. Regret was uncommon: over 93 percent of parents said they did not regret the decision, and 96 percent said they would make the same choice for another son.¹⁹ The low regret rate is worth noting but should be interpreted carefully: parents who chose against circumcision were not part of the same satisfaction analysis, and satisfaction may partly reflect the psychological comfort of having made a decision already carried out on one’s child.

Does It Affect Sexual Function

This is the question that generates the most heat online, and the research is genuinely mixed. The largest and most methodologically rigorous systematic review on the subject found that high-quality studies uniformly showed no overall adverse effect of circumcision on penile sensitivity, arousal, erectile function, ejaculatory control, orgasm, or sexual satisfaction.²⁰ A meta-analysis embedded in the same review supported these conclusions. One smaller study of men circumcised as adults found that sexual function scores did not change significantly after the procedure, and that most men reported no change in libido. About 38 percent actually reported improved penile sensation after circumcision, while 18 percent reported worse sensation. Almost 70 percent noticed less pain during intercourse.²¹

On the other side, a large self-report survey from Belgium found that circumcised men rated their glans as less sensitive, reported lower orgasm intensity, said they needed more effort to reach orgasm, and were more likely to describe unusual sensations such as numbness or tingling.²² The discrepancy between studies likely comes down to methodology. The Belgian study relied entirely on self-assessment and recruited through advocacy channels, which can introduce selection bias. The systematic review weighted studies by design quality and gave more credence to randomized trials and prospective cohorts. Neither approach is perfect. What can be said honestly is that the higher-quality evidence does not support the idea that circumcision dramatically impairs sexual function, but some men do report subjective changes, and it is not wrong to take those reports seriously.

The Procedure Itself

Neonatal circumcision in a clinical setting is a brief procedure, usually completed in under ten minutes. Three devices dominate in the U.S.: the Mogen clamp, the Gomco clamp, and the Plastibell device. A comparative analysis of outcomes across these three techniques found no significant differences in complication rates or emergency room returns. There were differences in how much pain was reported, but all three methods were well tolerated overall.²³ The most common complications of newborn circumcision are minor bleeding and local infection, both of which are typically manageable with basic wound care. Serious complications, such as removal of too much tissue or injury to the glans, are very rare in trained hands but do occur, and they are more likely when the procedure is performed outside a clinical setting by untrained practitioners.

Timing matters. Circumcision done in the newborn period is simpler, heals faster, and carries lower complication rates than circumcision done later in life. Adult circumcision requires general or regional anesthesia, involves sutures, and means several weeks of restricted activity and sexual abstinence during healing. This is one reason many medical organizations that support circumcision emphasize the neonatal window if the procedure is going to be done at all.

The Ethics Debate

Critics of routine infant circumcision ground their objection in two principles: bodily autonomy and the child’s inability to consent. The argument is straightforward: the child cannot choose, the foreskin is healthy tissue, and the procedure is irreversible, so it should be deferred until the boy is old enough to decide for himself. Proponents counter that many medical interventions on children, from vaccination to tonsillectomy, are performed without the child’s consent when they serve the child’s health interests, and that the medical benefits of neonatal circumcision are maximized when it is done early.²⁴

This disagreement is not purely theoretical. In 2012, a German court ruled that non-therapeutic circumcision of minors amounted to bodily harm, sparking a legislative scramble that ended with the German parliament passing a law explicitly permitting the practice. Several Nordic medical associations have called for an end to non-therapeutic infant circumcision on ethical grounds, while the American Academy of Pediatrics has stated that the health benefits of newborn circumcision outweigh the risks, though not enough to recommend universal circumcision. The gap between these positions reflects genuine differences in how societies weigh parental rights, religious freedom, disease-prevention data, and the interests of the child. No single answer can resolve the tension, which is why the debate persists.

The Cost Argument

In the U.S., circumcision is also defended on economic grounds. A cost-effectiveness analysis estimated that if the circumcision rate dropped to 10 percent, lifetime health care costs would rise by about $407 per male and $43 per female, driven by higher rates of HIV, HPV, HSV-2, and infant UTIs. Across a single annual birth cohort, net expenditure was projected to increase by over $500 million. Over ten cohorts, the additional costs would exceed $4.4 billion in net present value.²⁵ These projections model U.S.-specific STI prevalence and health care pricing; they would look different in a country with lower HIV rates or a differently structured health system. But in the American context, they have been influential in framing circumcision as a public health investment rather than just a personal choice.

It is worth noting that such models depend on assumptions about sexual behavior, STI prevalence, and treatment costs that can shift over time. The introduction of HPV vaccination, expanding access to PrEP for HIV, and changes in condom use all modify the background risk that circumcision is being measured against. An economic model built on 2010 STI rates may overstate the savings if vaccination and treatment programs continue to improve. Still, the direction of the cost finding, that circumcision prevents infections whose treatment costs money, is unlikely to flip even as the magnitude shifts.

Why the Foreskin Exists in the First Place

If circumcision provides health benefits, a fair question is why humans evolved a foreskin at all. The foreskin is not vestigial in the way an appendix is sometimes described. It protects the glans during development in the womb, keeps the surface moist, and contains a high density of nerve endings and specialized immune cells. In early human environments without clothing, the foreskin shielded the glans from abrasion, dirt, and drying. The health risks associated with the foreskin, STI transmission, bacterial overgrowth, phimosis, are largely problems of the post-puberty adult in specific sexual-transmission contexts. Evolution selects for traits that help organisms survive to reproduction, not for traits that optimize health at age 50. From an evolutionary standpoint, the foreskin was probably advantageous or neutral for most of human history, and the infections it now facilitates became consequential only with certain patterns of sexual behavior and population density.