Hirsutism is the growth of thick, dark hair in a male-type pattern on a woman’s body, typically appearing on the face, chest, back, and abdomen. It affects roughly 4% to 11% of women in the general population and is almost always driven by androgens, the group of hormones responsible for male-pattern hair development. While it’s not dangerous on its own, hirsutism often signals an underlying hormonal imbalance worth investigating.
Where the Hair Grows
The hair that defines hirsutism isn’t the fine, light fuzz that covers most of the body. It’s terminal hair: coarse, dark, and visible. It appears specifically in areas that respond to androgens. The most commonly affected sites are the upper lip, chin, chest, areolas, the line running down the center of the abdomen, lower back, buttocks, inner thighs, and external genitalia.
Doctors typically assess severity using the Ferriman-Gallwey scoring system, which rates hair density on a scale of 0 to 4 across 11 body areas including the lip, chin, chest, upper and lower abdomen, upper arm, forearm, thigh, lower leg, and upper and lower back. A total score of 8 or higher is generally considered diagnostic. This scoring helps distinguish mild cases that may only need cosmetic management from moderate or severe cases that call for medical treatment.
Hirsutism vs. Hypertrichosis
These two terms are easy to confuse, but they describe different things. Hirsutism refers specifically to excess hair in androgen-sensitive areas of a woman’s body. Hypertrichosis, by contrast, means excessive hair growth anywhere on the body, beyond what’s typical for a person’s age, sex, or ethnic background. Hypertrichosis can affect men or women and isn’t necessarily tied to hormones. If the excess hair is concentrated on your face, chest, or abdomen in a pattern that looks typically male, that points toward hirsutism.
The Most Common Cause: PCOS
Polycystic ovary syndrome accounts for the vast majority of hirsutism cases. Between 70% and 80% of women with PCOS experience hirsutism, making it the single most recognizable sign of the condition. In PCOS, the ovaries produce higher-than-normal levels of androgens. But the hormone levels alone don’t tell the whole story. How sensitive your individual hair follicles are to those androgens also plays a major role, which is why two women with similar hormone levels can have very different amounts of hair growth.
PCOS often comes with other symptoms: irregular periods, acne, difficulty losing weight, and sometimes trouble getting pregnant. If you’re noticing new or worsening facial and body hair alongside any of these, PCOS is the first thing a doctor will consider.
Other Hormonal Causes
When PCOS has been ruled out, several other conditions can produce excess androgens. One of the more common is non-classic congenital adrenal hyperplasia (NCCAH), a genetic condition where the adrenal glands produce androgens inefficiently due to a partial enzyme deficiency. Many women with NCCAH don’t know they have it until they develop hirsutism or have trouble conceiving. Screening involves a morning blood test for a hormone precursor called 17-OHP, taken during the first half of the menstrual cycle. Levels above a certain threshold will prompt further testing, sometimes including genetic analysis for confirmation.
Less commonly, androgen-producing tumors on the ovaries or adrenal glands can cause hirsutism. These tend to come on rapidly and be more severe, sometimes accompanied by voice deepening, muscle changes, or scalp hair loss. A sudden onset of significant hirsutism in a short period is a red flag that warrants prompt evaluation.
Idiopathic Hirsutism
In some women, all hormone levels come back normal and no underlying condition is found. This is called idiopathic hirsutism, meaning the hair follicles themselves are unusually sensitive to normal circulating androgen levels. It’s more common in certain ethnic backgrounds, particularly among women of Mediterranean, South Asian, and Middle Eastern descent. The hair growth is real and can be just as bothersome, even without a hormonal abnormality driving it.
How Hirsutism Is Evaluated
Evaluation usually starts with a physical exam using the Ferriman-Gallwey score, followed by blood work. Doctors will check total and free testosterone levels, along with other hormones that help narrow down the source. If PCOS is suspected, an ultrasound of the ovaries may be done. If adrenal hyperplasia is a possibility, specific adrenal hormone levels are measured, sometimes with a stimulation test that checks how the adrenal glands respond to a synthetic hormone signal.
The goal isn’t just to confirm that hirsutism is present. It’s to find out why, because the underlying cause shapes which treatment makes the most sense.
Medication-Based Treatment
For most premenopausal women, the first-line treatment is a combined oral contraceptive pill. These work by reducing the ovaries’ androgen production and increasing a protein in the blood that binds to free testosterone, making less of it available to stimulate hair follicles. The Endocrine Society’s clinical guidelines recommend trying this approach for at least six months before judging whether it’s working, because the hair growth cycle is slow and existing hairs need time to thin and fall out.
If the response after six months is still inadequate, an antiandrogen medication is typically added. These drugs block androgens from reaching hair follicles directly. They should not be used without reliable contraception, because they can cause birth defects in a male fetus. For women who can’t take hormonal contraceptives, particularly those with insulin resistance or related metabolic concerns, a medication that improves insulin sensitivity may be used instead, combined with lifestyle changes like regular exercise and weight management.
Treatment duration matters. Most guidelines recommend maintaining pharmacological therapy for at least 6 to 12 months, and many women stay on treatment longer. Hirsutism tends to return when medication is stopped if the underlying hormonal issue hasn’t resolved.
Hair Removal Options
Medication slows new hair growth, but it won’t eliminate hair that’s already there. That’s where physical removal methods come in, and the two permanent options are laser hair removal and electrolysis.
Laser hair removal targets the dark pigment (melanin) inside hair follicles, destroying them with concentrated light. It works best on dark hair and is effective across a range of skin tones, including darker skin when the right type of laser is used. In comparative studies, laser treatment achieved 70% to 77% hair reduction after five to six sessions, with each session lasting around 26 minutes and spaced roughly five weeks apart.
Electrolysis destroys individual follicles one at a time using an electric current delivered through a tiny probe. It’s effective on all hair and skin colors, including white, blonde, and red hair that laser can’t treat. The tradeoff is time: electrolysis requires significantly more sessions (around 24 on average versus 8 for laser), each session runs much longer (about 2.5 hours versus 26 minutes), and the total time spent in treatment adds up dramatically. Studies have found electrolysis achieves about 35% to 55% clearance in the same timeframe that laser achieves 70% or more.
For women with dark hair, laser is generally the faster and more effective starting point. For those with light or red hair, electrolysis is the only permanent option. Many women combine one of these methods with medication for the best overall results. Temporary methods like shaving, waxing, and threading remain useful for day-to-day management but don’t affect the underlying growth pattern.
The Emotional Side
Hirsutism carries a psychological burden that’s easy to underestimate from the outside. Visible facial hair in particular can cause significant distress, social anxiety, and reduced quality of life. Treatment decisions are guided not just by the clinical severity of hair growth but by how much it bothers you. A woman with a relatively low score on a clinical scale but high levels of distress deserves treatment just as much as someone with more extensive hair growth. Strong clinical support and realistic expectations about timelines, since visible improvement takes months rather than weeks, are important for sticking with a treatment plan long enough for it to work.