Women can develop features typically associated with men for several reasons, nearly all of which trace back to hormones, genetics, or both. The primary driver is androgens, a group of hormones that includes testosterone. Women naturally produce testosterone at levels between 15 and 46 ng/dL during their reproductive years, but when those levels rise or when the body becomes more sensitive to them, physical changes follow: thicker facial hair, a stronger jawline, a deeper voice, shifts in body fat, and thinning hair on the scalp.
Some of these changes are medical. Others are simply natural variation. Understanding the difference matters.
Androgens Shape Masculine Features
Testosterone and related androgens are responsible for most of the physical traits we read as “male.” During puberty in boys, a high ratio of testosterone to estrogen drives the lateral growth of cheekbones and the jaw, forward growth of the brow ridges, and lengthening of the lower face. These same hormones thicken the vocal folds, which is why male voices drop. When a woman’s body produces elevated androgens, or when her tissues are unusually responsive to them, some of these same processes can occur.
The result is what doctors call hyperandrogenism, and its most visible symptom is hirsutism: terminal (thick, dark) hair growing in a male pattern on the face, chest, abdomen, and back. Roughly 60% to 70% of women with polycystic ovary syndrome (PCOS) develop hirsutism, making PCOS the single most common cause. Beyond hair growth, elevated androgens can trigger severe acne, thinning hair on the top of the head (the same pattern seen in balding men), increased muscle mass, and a deeper voice.
PCOS Is the Most Common Cause
PCOS affects a significant percentage of women of reproductive age and is the leading reason women develop male-pattern hair growth. The condition involves a combination of elevated androgens, irregular or absent periods, and often (but not always) cysts on the ovaries. Because PCOS develops gradually, many women don’t realize their changing appearance has a hormonal explanation. Hair on the chin or upper lip might appear first, then spread to the chest or abdomen over months or years.
Clinicians assess the severity of this hair growth using the Ferriman-Gallwey scoring system, which grades terminal hair density from 0 to 4 at eleven body sites including the lip, chin, chest, upper and lower abdomen, back, arms, and thighs. A combined score of 8 or higher is generally considered diagnostic for hirsutism. But the system was originally designed around a predominantly white population, and it doesn’t always reflect what’s normal for women of different ethnic backgrounds.
Genetics and Ethnicity Play a Real Role
Not all visible hair growth in women signals a hormone problem. Natural variation across ethnic groups is substantial. In studies comparing facial hair growth, Indian women showed significantly more upper lip hair than any other group, while Caucasian women had the least. Caucasian Italian women had notably more facial hair than Caucasian British or American women. Japanese women had the least among East Asian groups. Importantly, skin color itself did not predict hair growth. Race and ethnicity did.
This means a woman with naturally heavier facial hair might be misdiagnosed with hirsutism if her doctor relies on scoring tools calibrated to a different population. What looks “masculine” by one cultural standard may be entirely normal physiology for another. The same applies to broader features like a prominent jawline, a square chin, or a naturally muscular build. These are influenced by genetic inheritance and don’t necessarily indicate a hormonal disorder.
Congenital Adrenal Hyperplasia
Congenital adrenal hyperplasia (CAH) is a group of inherited conditions in which the adrenal glands overproduce androgens. The classic form is usually detected at birth or in early childhood, but a milder version, called nonclassic CAH, often goes unnoticed until puberty or even adulthood. Symptoms include excessive body hair, a deeper voice, severe acne, thinning scalp hair, and absent or irregular periods. In children, nonclassic CAH can also accelerate skeletal development, causing bones to mature faster than normal for a child’s age.
Because nonclassic CAH mimics PCOS so closely, it’s sometimes missed. The distinction matters because the underlying cause is different (an enzyme deficiency in the adrenal glands rather than an ovarian issue), and treatment approaches differ.
Menopause Shifts the Hormonal Balance
After menopause, estrogen levels drop dramatically while testosterone declines more slowly. The result is a relative increase in androgen influence. Women lose about 60% of their total androgen pool by menopause, but because estrogen falls even further, the remaining testosterone carries more weight. This hormonal shift can cause new facial hair growth, worsening scalp hair loss, and acne, all in women who never had these issues before.
The voice can also change. Androgens target receptors in the vocal folds, and the post-menopausal shift toward androgen dominance can cause mild thickening of the vocal folds. The voice deepens slightly, sometimes enough to be noticeable. This is the same basic mechanism that deepens boys’ voices during puberty, just happening on a smaller scale.
Cortisol and Body Fat Redistribution
Cushing’s syndrome, caused by chronic overproduction of cortisol, reshapes the body in ways that can obscure typically feminine proportions. Women with Cushing’s accumulate fat preferentially in the abdomen and trunk rather than the hips and thighs. Visceral fat (the deep fat surrounding organs) increases significantly compared to healthy women, even after accounting for differences in total body fat, age, and height. The classic “buffalo hump” of fat at the upper back, a round face, and a thickened midsection can all make a woman’s body shape appear less characteristically feminine, especially when combined with the muscle wasting and skin thinning that cortisol also causes.
Anabolic Steroid Use
Women who use anabolic steroids, whether for athletic performance or bodybuilding, are essentially flooding their bodies with synthetic androgens. The physical changes can be dramatic and, in many cases, irreversible. Voice deepening occurs because androgens thicken the vocal folds permanently. Once the vocal cords have grown, stopping steroid use doesn’t reverse the change. Facial hair growth, jaw widening, and increased muscle mass are also common.
These effects mirror what happens in medical conditions like CAH or androgen-producing tumors, but they happen faster and are dose-dependent. The higher the dose and the longer the use, the more pronounced and permanent the masculinization.
Rare but Serious: Androgen-Producing Tumors
When masculine features develop rapidly in a woman, especially over weeks or months rather than years, the concern shifts to tumors. Both ovarian and adrenal tumors can produce large amounts of androgens. Sertoli-Leydig cell tumors of the ovary and adrenal carcinomas are among the types that cause sudden virilization: a noticeably deeper voice, rapid facial hair growth, increased muscle mass, and significant scalp hair loss. The speed of onset is the key warning sign. PCOS and CAH develop gradually. Tumor-driven changes tend to appear fast and progress quickly.
Postmenopausal women face a specific risk from ovarian hyperthecosis, a condition where ovarian tissue produces excess testosterone. This can also cause rapid masculinization and is sometimes mistaken for a tumor until imaging confirms the ovaries appear normal in structure.
What Determines Facial Structure
Beyond hair and voice, some women simply have bone structures that read as more masculine: a wider jaw, more prominent brow ridges, a larger nose. During puberty, androgens stimulate growth of the brow ridges and lower jaw. Every person, regardless of sex, has some level of androgen exposure during development. Women with naturally higher androgen levels during puberty, or with greater receptor sensitivity, may develop more angular facial features without having any medical condition at all.
Height, shoulder width, and hand size are also influenced by the balance of sex hormones during growth. These are continuous traits with enormous natural overlap between men and women. A tall woman with broad shoulders and a strong jaw may simply be at one end of the normal distribution for female development, not experiencing any hormonal abnormality.