Idiopathic hirsutism is hair growth of

• A. Hair growth due to hormonal imbalance
• B. Hair growth of unknown origin
• C. Hair growth due to chemotherapy
• D. Hair growth limited to scalp

Answer: (B)

Idiopathic hirsutism means hair growth of unknown origin. It refers to excessive terminal hair in androgen-sensitive areas when no hormonal imbalance or other identifiable cause can be found. That’s why the description “hair growth of unknown origin” is the best fit. In practice, clinicians rule out conditions with detectable hormonal excess or other causes before labeling it idiopathic. Hair growth due to hormonal imbalance would imply a measurable endocrine cause, while hair growth due to chemotherapy points to a drug-related effect. Hair growth limited to the scalp would not be considered hirsutism, since hirsutism involves body and facial hair in androgen-responsive regions.