Alopecia
Symptoms, Causes & Treatment
Alopecia (hair loss) affects around 8 million people in the UK. It ranges from temporary diffuse shedding to permanent pattern baldness and severe autoimmune hair loss. Early accurate diagnosis is key to effective treatment.
What is Alopecia?
Alopecia encompasses multiple distinct conditions: androgenetic alopecia (pattern baldness), alopecia areata (autoimmune), telogen effluvium (diffuse shedding), scarring alopecias, and hair loss secondary to nutritional deficiency, thyroid disease, or PCOS. The subtype determines treatment urgency, reversibility, and management options.
Symptoms of Alopecia
The pattern, distribution, and associated features of hair loss indicate the likely cause and urgency of treatment.
Hair loss from the scalp (diffuse or patterned) · Widening part or receding hairline · Thinning over the crown · Increased shedding (telogen effluvium) · Patchy circular bald areas (alopecia areata) · Associated itching, scaling, or scarring of the scalp
Sudden complete loss of eyebrows and eyelashes · Rapidly spreading hair loss affecting most of the scalp · Hair loss with systemic symptoms (significant weight loss, fever, fatigue) · Scarring alopecia with irreversible follicle destruction (urgent dermatology)
Rapidly spreading hair loss · Scalp redness, scaling, or tenderness with hair loss · Systemic symptoms alongside hair loss — seek urgent dermatology assessment.
What Causes Alopecia?
Alopecia has many causes, from genetic predisposition to autoimmune disease, nutritional deficiency, and scalp infection. Accurate diagnosis determines the most appropriate treatment.
Androgenetic alopecia (male and female pattern hair loss) is caused by genetic sensitivity of hair follicles to dihydrotestosterone (DHT). It is the most common cause of hair loss, affecting 50% of men by age 50 and 40% of women by age 70.
Alopecia areata is an autoimmune condition causing non-scarring patchy hair loss. It may progress to alopecia totalis (complete scalp loss) or alopecia universalis (all body hair). Associated with atopy, vitiligo, and thyroid disease. New JAK inhibitors (baricitinib) show high response rates.
Telogen effluvium is diffuse hair shedding triggered 2–3 months after a stressor: illness, childbirth, weight loss, surgery, or nutritional deficiency. It resolves spontaneously once the trigger is removed. Ferritin and B12 levels should be checked and corrected.
Scarring alopecias (lichen planopilaris, discoid lupus, central centrifugal cicatricial alopecia) cause permanent hair loss from follicular destruction. Early diagnosis and treatment are essential to halt progression. Requires urgent dermatology referral.
Tinea capitis (scalp ringworm) causes patchy, scaly, inflamed hair loss in children and immunocompromised adults. Diagnosed by scalp scraping and culture. Treated with oral antifungals (terbinafine, griseofulvin). Contacts should be screened.
Nutritional causes of hair loss include iron deficiency (most common), B12 deficiency, zinc deficiency, biotin deficiency, and protein malnutrition. Blood tests should include FBC, ferritin, B12, zinc, and TFTs. Correction of deficiency gradually restores hair density.
Key Risk Factors
Diagnosing Alopecia
Blood tests identify reversible causes. Scalp dermoscopy and biopsy differentiate subtypes. Hormonal investigations are indicated in women with features of hyperandrogenism.
Treatment for Alopecia
Treatment is targeted to the alopecia subtype. Reversible causes are treated first. Minoxidil and JAK inhibitors are the main pharmacological options. Surgical options are available for androgenetic alopecia.
Supportive Measures
Correct iron deficiency with ferrous fumarate. Address thyroid and hormonal causes. Avoid tight hairstyles and heat styling. Use gentle sulfate-free shampoo. Consider camouflage products or hairpieces while awaiting treatment response. Seek psychological support if hair loss is causing significant distress.
Long-Term Alopecia Management
Androgenetic alopecia is progressive and requires lifelong treatment. Alopecia areata may relapse and remit. JAK inhibitors are the most effective treatment for moderate-to-severe alopecia areata. Annual dermatology review maintains treatment optimisation.
When to Seek Help
Rapidly spreading hair loss covering most of the scalp · Hair loss with systemic symptoms (significant weight loss, fever, fatigue) · Suspected scarring alopecia with irreversible follicle destruction — seek urgent dermatology review.
See a GP for new or worsening hair loss, especially if progressing rapidly, associated with scalp changes, or if you have systemic symptoms. Blood tests to exclude reversible causes and dermatology referral can be arranged by your GP.
Preventing & Minimising Hair Loss
Many causes of hair loss are reversible through nutritional optimisation, treatment of underlying conditions, and avoidance of traction and heat damage.
Correct iron deficiency (target ferritin above 70 mcg/L) as the first step in managing hair loss. Iron is essential for normal hair cycling. Supplementation with ferrous fumarate 210mg twice daily and dietary iron optimisation restores hair density over 3–6 months.
Avoid hairstyles that place chronic traction on follicles (tight ponytails, braids, extensions). Traction alopecia causes permanent hair loss if sustained. Use wide-tooth combs, avoid excessive heat styling, and use gentle sulfate-free shampoos.
Have thyroid function checked annually if you have hair loss. Hypothyroidism and hyperthyroidism both cause diffuse hair shedding. Treating the thyroid abnormality restores hair density over 3–6 months.
Manage PCOS with lifestyle modification, metformin, and anti-androgen therapy where appropriate. Elevated androgens in PCOS cause female pattern hair loss in a Ludwig distribution. Treating the underlying hormonal imbalance slows hair loss progression.
Eat a varied diet rich in protein, iron, zinc, and B vitamins. Hair follicles are among the most metabolically active cells in the body and are highly sensitive to nutritional deficiencies. Avoid extreme calorie restriction.
See a GP early for new or rapidly progressing hair loss. Scarring alopecias require urgent dermatology referral, as follicular destruction is permanent and irreversible. Early treatment halts progression.
Getting Treatment for Alopecia
A GP can arrange blood tests to identify reversible causes, prescribe minoxidil, and refer to dermatology for specialist diagnosis and treatment. JAK inhibitors for severe alopecia areata are available through NHS dermatology.
Expert clinical advice, when you need it.
Alopecia — Frequently Asked Questions
The most common causes are androgenetic alopecia (pattern baldness), telogen effluvium (diffuse shedding after stress or illness), alopecia areata (autoimmune patchy loss), iron deficiency, and thyroid disease. A GP can arrange blood tests to identify reversible causes before dermatology referral.
Telogen effluvium causes diffuse shedding 2–3 months after a significant stressor: illness, surgery, childbirth, or rapid weight loss. It is usually temporary and resolves once the trigger is removed. Ferritin and thyroid function should always be checked in diffuse hair shedding.
Alopecia areata is an autoimmune condition causing sudden patchy hair loss. In most cases hair regrows spontaneously within 12 months, but recurrence is common. Treatments include intralesional steroids, topical immunotherapy, and JAK inhibitors (baricitinib, ritlecitinib) for severe extensive disease.
Ferritin below 70 mcg/L impairs normal hair growth. Iron is essential for follicular cell division. Many women with hair loss have ferritin in the low-normal range that still impairs hair cycling. Ferrous fumarate supplementation and dietary iron optimisation restores density over 3–6 months.
Scarring alopecia permanently destroys hair follicles. Early diagnosis is essential to halt progression. Hair loss with scalp redness, scaling, tenderness, or progressive spread should be assessed urgently by a dermatologist. Treatment can stop progression but cannot restore already destroyed follicles.
Treat reversible causes first (iron, thyroid, PCOS). Minoxidil 5% promotes growth in androgenetic alopecia and telogen effluvium. JAK inhibitors (baricitinib, ritlecitinib) are NICE-approved for moderate-to-severe alopecia areata. Intralesional corticosteroids treat localised patches of alopecia areata.
A GP can arrange blood tests (FBC, ferritin, TFTs, hormonal profile), treat reversible causes, prescribe minoxidil, and refer to dermatology for suspected scarring alopecia or significant hair loss requiring specialist treatment. An online consultation is a good first step for new hair loss.
Yes. Both hypothyroidism and hyperthyroidism cause diffuse telogen effluvium. Hair loss from thyroid disease reverses with effective treatment, usually over 3–6 months. TSH and TFTs should always be checked in unexplained diffuse hair shedding.