What is the cause of hirsutism (excessive hair growth) in females?

From the Guidelines

Hirsutism in females is most commonly caused by hormonal imbalances, particularly hyperandrogenism, which is often associated with polycystic ovary syndrome (PCOS) 1.

Causes of Hirsutism

The primary cause of hirsutism is the excess production of androgens, such as testosterone, which can be due to various factors, including:

• Polycystic ovary syndrome (PCOS)
• Congenital adrenal hyperplasia
• Cushing's syndrome
• Androgen-secreting tumors
• Certain medications

Diagnosis of Hirsutism

Diagnosing the underlying cause of hirsutism is crucial for effective treatment. The diagnostic workup may include:

• Physical examination
• Medical history
• Laboratory tests, such as:
  • Hormone level tests (e.g., testosterone, follicle-stimulating hormone (FSH), luteinizing hormone (LH))
  • Pelvic ultrasound to evaluate ovarian morphology
  • Other tests to rule out underlying medical conditions

Treatment of Hirsutism

Treatment options for hirsutism depend on the underlying cause and may include:

• Hormonal therapies, such as oral contraceptives containing ethinyl estradiol with anti-androgenic progestins, spironolactone, or finasteride, to reduce androgen levels or block their effects at hair follicles 1
• Hair removal methods, such as shaving, waxing, threading, depilatory creams, laser hair removal, or electrolysis
• Weight loss of 5-10% in overweight women to improve hormonal balance and reduce excessive hair growth
• Metformin (500-2000 mg daily) for women with PCOS to reduce insulin resistance and subsequently decrease androgen production It is essential to consult a healthcare provider for proper diagnosis and treatment, as facial hair can sometimes indicate underlying medical conditions requiring specific management 1.

From the Research

Causes of Hirsutism

• Hirsutism is usually a sign of an underlying endocrine abnormality, namely androgen excess 2
• The most common cause of androgen excess is the polycystic ovary syndrome (PCOS) 2
• Other less frequent causes of androgen excess include 21-hydroxylase-deficient nonclassic adrenal hyperplasia, the hyperandrogenic insulin-resistant acanthosis nigricans syndrome, androgen-secreting tumors, and androgenic drug intake 2
• Approximately 5-15% of hirsute patients have "idiopathic hirsutism" with normal ovulatory function and androgen levels 2

Factors Contributing to Hirsutism

• There is a strong familial predilection for hirsutism, primarily because the underlying endocrine disorders and the factors regulating the development of hair growth have a strong genetic component 2
• Androgen receptor activity and 5alpha-reductase activity also play a role in the development of hirsutism 2

Prevalence of Hirsutism

• Hirsutism affects between 5% and 15% of women, depending on the definition 2
• Approximately 80% of women are affected by the presence of excessive hair growth in a 'male-like' pattern 3
• Up to 40% of the general female population have some degree of unwanted facial hair 4

Associated Conditions

• Hirsutism is often associated with ovulatory dysfunction, adrenal hyperplasia, diabetes, and thyroid hormone abnormalities 2
• Polycystic ovary syndrome (PCOS) is a common underlying condition in women with hirsutism 2, 5