Humans lost most of their body hair over the course of evolution, yet a thick patch stayed in one of the most private spots on the body. Scientists think it stayed because it does a job, though they still debate which one. The proposed answers range from plain mechanics, like protecting skin, to the role of scent and attraction. None of them is fully proven, and most are educated guesses built from how the body works.
A Cushion Against Friction and Irritation
Genital skin is thin and sensitive compared with skin on most of the body. Pubic hair sits between skin surfaces and cuts down on rubbing during sex and everyday movement.1Elite Daily. If Chafing During Sex Is An Issue, Here Are 7 Products To Help Save Your Skin Hair slides against hair more easily than skin slides against skin, and the natural oils in hair add some slip.2Elite Daily. If Chafing During Sex Is An Issue, Here Are 7 Products To Help Save Your Skin
Hair also keeps skin from pressing directly on skin, which may reduce trapped moisture that feeds irritation.3PubMed Central. Effects of pubic hair grooming on women’s sexual health: a systematic review and meta-analysis4Love Wellness. Why Do We Have Pubic Hair? Health Insights So if you shave and notice chafing, the missing cushion is a likely reason.
Friction irritation usually looks like diffuse redness, a raw or stinging feeling, or mild swelling on the outer skin. It often appears after sex, a long walk, or a workout, or after tight jeans or leggings rub against newly shaved skin. It tends to sit where skin rubs, such as the folds between the thighs and groin. Separate, tender bumps centered on a single hair are more likely ingrown hairs or irritated follicles, which are a different problem with a different fix. Friction soreness usually settles within a few days once the rubbing stops, and it often comes back each time the hair is removed.
If you remove hair and want fewer problems, a few habits help. Trimming short keeps some cushion while still looking neat. Lubricant during sex replaces some of the lost slip. Looser, breathable underwear lowers rubbing and moisture, and giving irritated skin a break before removing hair again lets it recover.
Washing the area as you normally would keeps it clean whether or not hair is present. Removing it is a personal choice, not a hygiene requirement.
Holding and Spreading Body Scent
Humans have lost most of a type of scent-producing sweat gland.5JAMA. PUBIC APOCRINE GLANDS AND ODOR They survive in a few places, though, including the armpits, the genital and groin area, and the nipples.6JAMA. PUBIC APOCRINE GLANDS AND ODOR These glands are tied to hair follicles, so they cluster where body hair is thickest.7The Guardian. What is the point of pubic hair?
Hair holds the glands’ secretions close to the skin, where bacteria break them down.8The Guardian. What is the point of pubic hair? As sweat evaporates, that breakdown releases scent compounds that some researchers think may act as signals to other people.9The Guardian. What is the point of pubic hair? Warmth trapped under the hair may also help these compounds turn into a gas and spread.10The Conversation. Pubic hair: beyond brazilians, more than manscaping One theory is that this scent could help attract a sexual partner.11SELF. This Is Why You Have Pubic Hair Whether human pheromones actually change attraction is still unproven.
Fresh secretions from these glands are mostly odorless when they first reach the skin, so the smell people notice is not the sweat itself. Skin bacteria feed on the fats and proteins in the secretions and release smelly byproducts, and that is where body odor comes from. Hair gives the bacteria a larger surface to live on and holds the secretions in place, so odor builds up faster in hairy areas.
Some scent in this area is normal and not a sign of poor hygiene. A strong, fishy, or suddenly new smell may signal an infection worth getting checked. Plain washing is enough, and harsh scented products can irritate.
A Visible Sign of Sexual Maturity
Humans are unusual among primates in having a thick bush of wiry hair around the genitals.12Scientific American. A bushel of facts about the uniqueness of human pubic hair One researcher suggests a main reason it evolved was to show visibly that a person is sexually mature.13Scientific American. A bushel of facts about the uniqueness of human pubic hair That fits the timing, since the patch appears at puberty, right when a person becomes able to reproduce.
This idea differs from the scent one in how it would work. Smell only works at short range, while a visible patch could signal maturity from a distance or at the moment of undressing. The two ideas don’t compete, and the same patch of hair could do both jobs. Neither has been tested directly in people.
Warmth, Moisture, and Germs
Some gynecologists say pubic hair helps keep the area warm in cold conditions and helps sweat evaporate in heat.14HUM Nutrition Blog. The Function of Pubic Hair In skin folds with many sweat glands, body hair acts as a natural regulator of temperature and moisture.15Love Wellness. Why Do We Have Pubic Hair? Health Insights In cold, hair may trap a thin layer of warm air next to the skin, which slows heat loss in a small area. In heat, it may wick sweat away so it evaporates instead of pooling. The effect is likely small, since the patch covers a limited area and clothing does most of the temperature work.
Pubic hair may also act as a barrier that keeps some outside bacteria away from the genitals.16HUM Nutrition Blog. The Function of Pubic Hair That claim comes mostly from wellness sources and has little direct testing. The body’s main defenses against genital infection are intact skin, mucous surfaces, and the natural bacteria that live there, not hair. Studies of grooming also struggle to separate the effect of losing hair from the effect of small razor nicks or wax burns. So the barrier role is plausible but not established. Pubic hair carries its own bacterial community, more varied than the one on scalp hair and less shaped by the outside environment.17PubMed Central. Metagenomic analyses of bacteria on human hairs: a qualitative assessment for applications in forensic science
Why It Grows at Puberty and Thins With Age
Androgens, male-type hormones that both sexes make, are the main controller of hair growth.18PubMed. Androgens and hair growth They turn small follicles that make fine, near-invisible hair into follicles that make thick, dark hair.19PubMed. Androgens and hair growth Around puberty they trigger pubic and underarm hair in both sexes.20PubMed. Androgens and hair growth The adrenal glands start making more of these hormones early, before most other signs of puberty, so pubic hair, body odor, and acne often show up around the same time.21AMBOSS. Puberty
The same male-type hormones that switch on thick pubic hair also activate the scent glands in the groin and underarms. That is why a teen often notices new body odor just as hair appears.
Later in life, slow, even thinning of pubic hair from around age 40 to 50 is a normal part of aging.22Elithair. Pubic Hair Loss: Pubic Hair With Age, Causes and What You Should Know It follows the drop in estrogen at menopause in women and the gradual fall in testosterone in men.23Elithair. Pubic Hair Loss: Pubic Hair With Age, Causes and What You Should Know Gradual thinning is expected, while sudden or patchy loss is worth asking a doctor about. Greying of pubic hair with age is normal too, just like on the scalp.
Pubic hair in a young child, well before typical puberty ages, is worth a pediatrician visit. New heavy hair growth in an adult woman can reflect a hormone change.
Why It’s Curly, Coarse, and Shaped Differently
The outer protective layer of pubic hair has more scales than scalp hair, making it thicker and coarser. That wiry texture may suit its job as a durable cushion.
Texture has a downside after shaving. Curly, coarse hair is more likely to curl back into the skin, which is why shaving the area so often causes bumps. Shaving with the grain or trimming instead lowers the risk.
Pubic hair also grows in several patterns, from a flat top edge to one that runs up toward the navel.24Anthropologischer Anzeiger. Sex differences in adult pubic hair distribution in Nigeria In one large group of adults, the pattern pointing up toward the navel appeared in about half of men and about 1 in 10 women.25Anthropologischer Anzeiger. Sex differences in adult pubic hair distribution in Nigeria So a woman with hair extending toward the navel is within a normal range.
What Removing It Means for Your Health
In a large national survey, people who had ever groomed reported having had an STI about 1.8 times as often as non-groomers, after accounting for age and number of partners.26PubMed. Correlation between pubic hair grooming and STIs: results from a nationally representative probability sample The link was strongest for skin-spread infections like herpes and genital warts among people who removed all hair or groomed very often, at about 3.5 to 4.4 times.27PubMed. Correlation between pubic hair grooming and STIs: results from a nationally representative probability sample This shows a link, not proof that grooming causes infection. Shaving and waxing can cause tiny cuts that may let skin-to-skin infections in more easily.
If you choose to groom, trimming with clippers avoids the nicks razors cause. With a razor, use a clean, sharp one and shave in the direction of growth. Avoid grooming right before sex so tiny cuts can heal first, and keep using condoms, though they don’t cover all skin.
Pubic lice live in coarse hair, yet groomers in the same survey reported a history of lice more often, not less.28PubMed. Correlation between pubic hair grooming and STIs: results from a nationally representative probability sample Many people assume removing hair lowers the risk, but grooming habits are tied to other things, such as number of partners.
After grooming, painful bumps, pus, or spreading redness can mean infection. New sores or warts need checking rather than being assumed to be razor burn. Persistent itching may be lice or a fungal infection.