• Look for excessive terminal hair in androgen-dependent areas including the face, chest, linea alba, lower back, buttocks, and anterior thighs.
• Some hair growth in androgen dependent areas is normal, and there is no clear cut-off for defining excessive hair growth.
• It is important to differentiate between terminal hair (which is dark, thick, and coarse) and vellus hair (which is soft, fine, and unpigmented). Vellus hair does not indicate hirsutism.

• Hypertrichosis is excessive hair growth distributed in a generalized, nonsexual pattern.
• It may be hereditary or drug-induced.
• It is not caused by excess androgen.

[Martin et al, 2008]

• Ask about, and look for, features of polycystic ovary syndrome (PCOS) — oligomenorrhoea or amenorrhoea, infertility, acne, hair loss from the scalp, central obesity, acanthosis nigricans.
• For information on the diagnosis of PCOS, see the section on Diagnosis in the CKS topic on Polycystic ovary syndrome.
• Ask about, and look for, features of an androgen secreting tumour — sudden onset or rapid progression of hair growth, severe hirsutism, signs of virilization (hair loss from the scalp, voice deepening, increased muscle bulk, clitoromegaly), a pelvic or abdominal mass.
• Urgently refer the woman if an androgen-secreting tumour is clinically suspected.
• Ask about, and look for, features of Cushing's syndrome — for example: weight gain in the face (moon face), neck region, upper back, and torso; stretch marks; easy bruising; and proximal muscle weakness.
• Refer the woman if Cushing's syndrome is suspected.
• Consider checking free cortisol levels (using a 24-hour urine collection) or performing a dexamethasone suppression test before the outpatient appointment.
• Ask about current medication, including any use of anabolic steroids.
• In women with mild hirsutism and no other signs of PCOS or other underlying condition:
• Investigations are not usually necessary.
• In women with moderate-to-severe hirsutism and no other signs of PCOS or other underlying condition:
• Measure plasma testosterone.
• If the testosterone level is greater than 5 nanomol/L, seek specialist advice.
• Consider screening for late-onset congenital adrenal hyperplasia in women who are at high risk (for example those with a positive family history, or from a high-risk ethnic group [such as Ashkenazi Jewish, Hispanic, and Slavic people]), especially if they wish to conceive.
• Measurement of early morning 17-hydroxyprogesterone is recommended — check with the local laboratory for details of when and how this test should be performed.
• Refer the woman to an endocrinologist if 17-hydroxyprogesterone levels are elevated.

Underlying conditions

• The recommendations to ask about, and look for, features of polycystic ovary syndrome (PCOS), androgen-secreting tumours, and Cushing's syndrome are based on the fact that these are known underlying causes of hirsutism.

Medication

• Certain drugs, including danazol, sodium valproate, and anabolic steroids can cause hirsutism [Martin et al, 2008].

Investigations for mild hirsutism with no other signs of PCOS or other underlying condition

• The recommendation that investigations are not necessary in women with mild hirsutism and no other signs of PCOS or other underlying condition is in line with recommendations from an Endocrine Society clinical practice guideline, based on very low quality evidence [Martin et al, 2008]. This is supported by the opinion of CKS expert reviewers.

Checking testosterone levels in women with moderate-to-severe hirsutism and no other signs of PCOS or other underlying condition

• The recommendation to check testosterone levels in women with moderate-to-severe hirsutism and no other signs of PCOS or other underlying condition is in line with recommendations from an Endocrine Society clinical practice guideline, based on very low quality evidence [Martin et al, 2008].

Screening for late-onset congenital adrenal hyperplasia

• The recommendation to consider screening for late-onset congenital adrenal hyperplasia in women at high risk is based on a narrative text on rational testing [Sathyapalan and Atkin, 2009].
• Around 1–10% of women with hyperandrogenaemia have late-onset congenital hyperplasia, which is clinically indistinguishable from PCOS.
• The prevalence is higher in Hispanic, Ashkenazi Jewish, and Slavic people. Therefore, screening in this group seems sensible.
• Identification of late-onset congenital adrenal hyperplasia in women who are trying to conceive is important so that glucocorticoid treatment can be initiated in the peri-conceptual period [Koulouri and Conway, 2009].