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Body‑hair changes are an important clinical clue to metabolic and endocrine disorders.
Included in the RCGP curriculum under Metabolic problems and endocrinology.
Presentations range from:
Excess hair growth – hirsutism (male-pattern) or hypertrichosis (generalised).
Hair loss or thinning – alopecia (patchy or diffuse).
May indicate underlying hormonal imbalance (e.g., androgen excess, thyroid dysfunction, adrenal or pituitary disorders).
Can be physiological (puberty, pregnancy, menopause) or pathological (PCOS, Cushing’s, androgen-secreting tumours).
Often associated with psychological distress → impacts quality of life.
Early recognition → appropriate investigation, management, and referral.
Anagen (growth phase): Active hair production; lasts years on scalp.
Catagen (involution phase): Follicle regression; lasts weeks.
Telogen (resting phase): Shedding phase; lasts months.
Convert vellus hair → terminal hair (thicker, pigmented).
↑ Sebum production and anagen duration on body hair.
Shorten anagen on scalp → may contribute to androgenic alopecia.
Follicle sensitivity varies by individual and ethnicity.
Ferriman–Gallwey score: Rates 9 androgen‑sensitive areas (e.g., upper lip, chin, chest).
Score ≥8 = hirsutism in UK women (NICE CKS).
Thyroid hormones: Regulate follicle metabolism and hair cycle.
Cortisol, GH, prolactin: Direct impact on growth cycle.
Oestrogen ↓ (post‑menopause): Increases androgen sensitivity → hair pattern changes.
History – Assessment
| History Domain | Key Points |
|---|---|
| Onset & Progression | Gradual onset from puberty → likely PCOS; rapid onset/progression → consider androgen‑secreting tumour (NICE CKS) |
| Distribution / Pattern | Male‑pattern (face, chest, abdomen) → androgen excess; generalised → hypertrichosis; use Ferriman–Gallwey score (≥8 = hirsutism in UK women; thresholds vary by ethnicity) |
| Menstrual & Reproductive History | Irregular/absent menses → PCOS, hyperprolactinaemia, thyroid disorder; infertility; menopause timing |
| Associated Endocrine Symptoms | Weight ↑/↓, acne, voice deepening, muscle weakness, galactorrhoea, heat/cold intolerance, polyuria/polydipsia, salt craving, mood changes |
| Medication History | Steroids, progestogens, minoxidil, valproate, phenytoin, cyclosporine |
| Family & Ethnicity | Familial hair patterns (e.g., PCOS, CAH); ethnic variation in baseline hair growth |
| Psychosocial Impact | Assess distress and quality‑of‑life impact (even mild changes can be significant) |
Ecamination
| Examination Domain | Key Points |
|---|---|
| General (Vital signs & BMI) | Check BMI, blood pressure → screen for metabolic syndrome, Cushing’s, hypothyroidism |
| Skin & Hair | Assess distribution, texture (coarse vs fine), scalp vs body hair; note acne, seborrhoea, striae, hyperpigmentation (Addison’s), acanthosis nigricans |
| Signs of Virilisation | Male‑pattern baldness, voice deepening, ↑ muscle bulk, clitoromegaly |
| Pituitary / Thyroid Signs | Visual field defects, galactorrhoea, goitre, tremor (thyroid dysfunction) |
| Peripheral Circulation | Shiny skin, ↓ hair growth, cold limbs → consider peripheral arterial disease (PAD) |
Causes of Excess Body Hair Growth
Excessive hair growth (hirsutism or hypertrichosis) may be physiological, medication-related, or due to endocrine/metabolic disorders. In women, polycystic ovary syndrome (PCOS) is most common; rapid onset or virilisation suggests androgen-secreting tumours (red flag). Hypertrichosis in men is rare and usually secondary to systemic disease or drugs.
| Category | Examples & Clinical Clues |
|---|---|
| Common | PCOS – Most common; puberty onset; irregular menses; acne; insulin resistance; ± obesity |
| Idiopathic | Idiopathic hirsutism – Normal androgens; ↑ follicle sensitivity; ~15% of cases |
| Red Flags / Less Common |
Androgen-secreting tumours – Rapid onset; virilisation (voice deepening, ↑ muscle mass, clitoromegaly); pelvic/abdominal mass Congenital adrenal hyperplasia – Non-classical forms; hirsutism + infertility Cushing’s syndrome – Weight ↑, purple striae, truncal obesity, new facial/body hair Acromegaly – Coarse features, enlarged hands/feet, ↑ body hair Hyperprolactinaemia – Galactorrhoea, menstrual disturbance ± hirsutism |
| Thyroid Disorders | Rare cause; severe hypothyroidism → coarse hair; lateral eyebrow loss |
| Medications | Cyclosporine, minoxidil, phenytoin, anabolic steroids, corticosteroids, valproate, progestogens |
| Category | Examples & Clinical Clues |
|---|---|
| Hypertrichosis (non-androgen dependent) | Rare; may occur with hypothyroidism, porphyria, or drugs (e.g., minoxidil) |
| Familial / Ethnic Variants | Often physiological; only significant if exceeds familial/ethnic norms |
Causes of Hair Loss or Thinning
Hair loss can be diffuse or patterned, scarring or non-scarring. It may arise from endocrine disorders (e.g., thyroid disease, hypogonadism), nutritional deficiencies, systemic illness, or medications. Recognising the pattern and associated systemic features helps direct investigation and management.
| Condition | Features |
|---|---|
| Androgenetic alopecia | Male or female pattern baldness; androgen-driven; gradual scalp thinning in characteristic distribution |
| Hypothyroidism | Slow-growing, coarse, dry, brittle hair; diffuse alopecia; loss of outer third of eyebrows |
| Hyperthyroidism (thyrotoxicosis) | Fine, silky hair; diffuse non-scarring alopecia due to shortened anagen phase |
| Addison’s disease | Loss of pubic and axillary hair due to ↓ adrenal androgens; associated hyperpigmentation, hypotension, weight loss |
| Hypogonadism / androgen deficiency (men) | Loss of armpit and pubic hair; ↓ beard growth; erectile dysfunction; ↓ muscle mass |
| Pituitary hormone deficiency | Generalised body-hair loss; features of hypopituitarism (fatigue, amenorrhoea, weight changes) |
| Peripheral arterial disease (PAD) | Hair loss on legs/feet; shiny skin; brittle nails; associated with diabetes and vascular risk factors |
| Autoimmune alopecia | Alopecia areata (patchy hair loss); may coexist with autoimmune thyroiditis or vitiligo |
| Medications / toxins | Chemotherapy, retinoids, valproate, heavy metals; often diffuse telogen effluvium |
| Nutritional deficiencies | Iron deficiency, zinc deficiency, protein malnutrition → diffuse thinning; associated pallor or fatigue |
Investigations for Body Hair Changes
Investigations are guided by history and examination findings. Start with basic hormonal and metabolic screens in primary care; escalate to targeted endocrine tests or imaging if red flags (rapid onset, virilisation, severe alopecia) are present.
| Test | Purpose / Clinical Clues |
|---|---|
| Total Testosterone | First-line in women with abnormal Ferriman–Gallwey score; >4 nmol/L → refer to endocrinology (NICE CKS) |
| SHBG & Free Androgen Index | Confirms hyperandrogenism; useful if total testosterone borderline |
| DHEAS | Elevated in adrenal tumours or congenital adrenal hyperplasia (CAH) |
| 17-Hydroxyprogesterone | Screens for non-classical CAH; >6 nmol/L suggests diagnosis |
| LH, FSH, Prolactin, Oestradiol | Differentiates PCOS (↑ LH:FSH ratio) from hyperprolactinaemia or ovarian failure |
| Thyroid Function Tests (TSH, Free T4) | Assess hypo-/hyperthyroidism causing hair loss or thinning |
| Cortisol / Dexamethasone Suppression Test | For suspected Cushing’s syndrome (weight gain, striae, proximal weakness) |
| Glucose Tolerance / Fasting Insulin | Screens for insulin resistance, metabolic syndrome (PCOS) |
| Pelvic Ultrasound | Detects polycystic ovaries or ovarian masses |
| CT / MRI (Adrenal or Pituitary) | For suspected tumours (e.g., high testosterone, DHEAS, or cortisol levels) |
| Additional Tests | Ferritin, vitamin D, zinc for diffuse hair loss; lipid profile for metabolic risk |
Presentation
Body-hair changes often present for cosmetic reasons but may indicate endocrine or metabolic disease.
Look for systemic symptoms (e.g., weight change, menstrual disturbance, skin changes).
Definitions
Hirsutism: Androgen-dependent terminal hair growth in male-pattern areas (face, chest, back).
Hypertrichosis: Generalised non-androgen dependent hair growth.
Alopecia: Hair loss or thinning; may be diffuse or patterned.
Common Causes
PCOS and idiopathic hyperandrogenism account for most female hirsutism.
Endocrine causes of hair loss: thyroid disease, Addison’s, hypogonadism, pituitary disorders, PAD.
Red Flags
Rapidly progressive hirsutism or virilisation → suspect androgen-secreting tumour → urgent endocrine referral (NICE CKS).
Management Principles
Treat underlying cause (e.g., thyroid replacement, glucocorticoids, testosterone therapy).
Address psychological impact; provide reassurance and realistic expectations (hair changes may take months to improve).
Lifestyle and cosmetic measures: weight loss in PCOS, hair removal, combined oral contraceptives, consider anti-androgens with specialist input.
Patient-centred Care
Consider mental health, cultural factors, and contraception/pregnancy status when prescribing hormonal therapy.
Provide written information; signpost to reliable resources (e.g., NHS, British Association of Dermatologists).
RCGP – Metabolic Problems and Endocrinology Topic Guide (2025). Available at: https://www.rcgp.org.uk/getmedia/ff4cdd2d-7b67-4a9a-a004-aff01365c268/Metabolic-problems-endocrinology-SCCG-2025.pdf
NCBI – Hair Follicle Physiology and Hormonal Regulation. PMC10933461. Available at: https://pmc.ncbi.nlm.nih.gov/articles/PMC10933461/
PhysioPedia – Metabolic and Endocrine Disorders. Available at: https://www.physio-pedia.com/Metabolic/Endocrine_Disorders
RCGP eLearning – Mental Health and Endocrinology. Available at: https://elearning.rcgp.org.uk/course/search.php?search=mental+health
RCGP – Metabolic Problems and Endocrinology Final Topic Guide. Available at: https://www.rcgp.org.uk/getmedia/31e672e1-7683-49a6-a978-ad9158d9c2dd/Metabolic-Problems-and-Endocrinology-final.pdf
Society for Endocrinology – Guidance on Hirsutism and Endocrine Hair Disorders. Available at: https://www.endocrinology.org/media/1381/077.pdf
RCGP – GP Curriculum Clinical Topic Guides. Available at: https://www.rcgp.org.uk/mrcgp-exams/gp-curriculum/clinical-topic-guides
NCBI – Endocrine Disorders and Hair Changes Review. PMC11139569. Available at: https://pmc.ncbi.nlm.nih.gov/articles/PMC11139569/
GMC – Topic Guides 2025. Available at: https://www.gmc-uk.org/-/media/documents/topic-guides-2025_pdf-110256640.pdf
ScienceDirect – Recent Advances in Endocrinology and Hair Disorders (2024). Available at: https://www.sciencedirect.com/science/article/pii/S0306453024000830
NICE Clinical Knowledge Summary – Hirsutism in Women (2023). Available at: https://cks.nice.org.uk
YourHormones.info – Causes of Excess Hair Growth (Society for Endocrinology). Available at: https://www.yourhormones.info
American Academy of Family Physicians – Evaluation and Treatment of Hirsutism. Available at: https://www.aafp.org
British Thyroid Foundation – Hypothyroidism and Hair Loss. Available at: https://www.btf-thyroid.org
NHS – Peripheral Arterial Disease and Hair Loss. Available at: https://www.nhs.uk
Mayo Clinic – Addison’s Disease Overview. Available at: https://www.mayoclinic.org
Cleveland Clinic – Male Hypogonadism. Available at: https://my.clevelandclinic.org
Cancer.org – Pituitary and Adrenal Disorders Affecting Hair. Available at: https://www.cancer.org
