Hirsutism
Hirsutism is excess terminal (coarse, pigmented) hair growth in a male-pattern distribution in women, scored using the modified Ferriman-Gallwey system, per the Endocrine Society 2018 Clinical Practice Guideline.
Symptoms
Coarse hair growth on the face, chest, or back, often alongside acne or irregular periods when the underlying cause is PCOS.
Causes and risk
PCOS accounts for roughly 70-80% of cases; idiopathic hirsutism (elevated hair-follicle sensitivity to normal androgen levels) accounts for another 5-20%. Rarer but more serious causes -- androgen-secreting tumors, congenital adrenal hyperplasia -- need to be considered, especially with rapid onset.
How it is evaluated
The Ferriman-Gallwey score quantifies severity (the 2023 International PCOS Guideline favors a lower cutoff of 4-6 over the older ≥8 threshold); labs look for the underlying cause once PCOS and other possibilities are on the differential.
Treatment
Combined oral contraceptives are first-line when pregnancy isn't desired; anti-androgens (spironolactone) are added when response is inadequate. Mechanical hair removal (laser, electrolysis) addresses the hair directly regardless of the hormonal cause.
When to seek care
Rapid onset over months (rather than years), voice deepening, increased muscle mass, or clitoral enlargement suggest virilization from a more serious underlying cause and need prompt evaluation.