Medical Conditions That Cause Hair Loss in Men

Medical conditions that cause hair loss in men range from hormonal imbalances and autoimmune disorders to nutritional deficiencies and chronic systemic disease. While male pattern baldness (androgenetic alopecia) accounts for around 95% of hair loss in men, approximately 5% of cases stem from underlying health issues that require diagnosis and management by a GP or specialist [1]. Understanding the difference between genetic hair loss and medically driven shedding is essential for effective treatment.

Common Medical Conditions That Cause Hair Loss in Men

Several systemic and dermatological conditions can trigger significant hair shedding. Thyroid disorders—both hyperthyroidism and hypothyroidism—disrupt the hair growth cycle, leading to diffuse thinning across the scalp [1]. Autoimmune conditions such as alopecia areata cause the immune system to attack hair follicles, resulting in patchy, often circular bald spots that can progress to total scalp or body hair loss.

Iron deficiency anaemia, low ferritin, and vitamin D deficiency are frequently overlooked nutritional causes of hair loss in men. Chronic illnesses including diabetes, lupus, and inflammatory skin conditions like seborrhoeic dermatitis or scalp psoriasis can also impair follicle health. If you notice sudden, patchy, or rapid hair loss, arrange blood tests and a clinical examination with your GP to rule out these medical conditions that cause hair loss in men.

• Thyroid dysfunction (hypo- or hyperthyroidism) affecting hair cycle regulation
• Alopecia areata and other autoimmune disorders targeting follicles
• Iron deficiency anaemia and low serum ferritin levels
• Vitamin D deficiency impairing follicle stem cell function
• Chronic systemic diseases such as diabetes and lupus

How Medical Conditions That Cause Hair Loss in Men Differ from Pattern Baldness

Male pattern baldness follows a predictable, gradual progression driven by genetic sensitivity to dihydrotestosterone (DHT), typically affecting the temples, crown, and vertex [2]. In contrast, medically driven hair loss often presents as diffuse thinning across the entire scalp, sudden onset shedding (telogen effluvium), or patchy bald spots with smooth skin (alopecia areata).

Blood tests can identify hormonal imbalances, nutritional deficiencies, and markers of autoimmune or inflammatory disease. A dermatologist may perform a scalp biopsy or pull test to confirm the diagnosis. Treating the underlying condition—whether that means thyroid hormone replacement, iron supplementation, or immunosuppressive therapy—can restore normal hair growth, whereas androgenetic alopecia requires ongoing pharmacological management with finasteride or minoxidil [2].

When to See Your GP

Arrange an appointment if you experience rapid hair loss over weeks, patchy bald areas, scalp redness or scaling, hair loss accompanied by fatigue or weight changes, or if over-the-counter treatments have no effect after six months. Your GP can order thyroid function tests, full blood count, ferritin, vitamin D, and autoimmune markers to identify medical conditions that cause hair loss in men.

Diagnosing Medical Conditions That Cause Hair Loss in Men

Diagnosis begins with a detailed clinical history and physical examination of the scalp. Your GP will ask about the onset, pattern, and duration of hair loss, family history, medications, recent illness, and symptoms such as fatigue, weight change, or joint pain. Blood tests typically include thyroid-stimulating hormone (TSH), free T4, serum ferritin, full blood count, vitamin D, and sometimes testosterone and autoantibody screens [3].

Dermatology referral may be warranted for atypical presentations, scarring alopecia, or when initial investigations are inconclusive. A scalp biopsy can differentiate between inflammatory, infectious, and autoimmune causes. Early and accurate diagnosis of medical conditions that cause hair loss in men enables targeted treatment and, in many cases, full or partial hair regrowth once the underlying disorder is controlled.

1. Clinical history and scalp examination by your GP or dermatologist
2. Blood tests: TSH, free T4, ferritin, full blood count, vitamin D, autoantibodies
3. Pull test or scalp biopsy if the diagnosis remains unclear
4. Referral to endocrinology or rheumatology if systemic disease is suspected

Cured Pharmacy Hair Loss Treatments Comparison

Treatment Options for Medical Conditions That Cause Hair Loss in Men

Treatment is always directed at the underlying cause. Thyroid disorders are managed with levothyroxine (hypothyroidism) or antithyroid drugs (hyperthyroidism); hair regrowth typically follows once thyroid hormone levels normalise [3]. Iron and vitamin D supplementation can reverse deficiency-related shedding within three to six months. Alopecia areata may be treated with topical or intralesional corticosteroids, topical immunotherapy, or systemic agents in severe cases.

For men with confirmed male pattern baldness rather than a medical cause, prescription treatments such as finasteride 1mg (including Propecia) and topical minoxidil 5% foam (Regaine Extra Strength) are clinically proven to slow hair loss and promote regrowth [4]. At Cured Pharmacy, finasteride 1mg tablets start from £12.49 for 28 tablets, and all prescription medicines are supplied only after a free online consultation with a UK prescriber. Always consult your GP before starting any hair loss treatment if you have an underlying health condition.

Cured Pharmacy Hair Loss Treatments

Cured Pharmacy offers a range of UK-licensed hair loss treatments for male pattern baldness, all dispensed by our GPhC-registered team under the supervision of superintendent pharmacist Tarun Kumar (GPhC 2233073). Finasteride 1mg and Propecia 1mg are prescription-only oral tablets taken once daily; minoxidil 5% foam is applied to the scalp twice daily. Dutasteride 0.5mg capsules are used off-label for hair loss at the prescriber's discretion. New patients receive 20% off their first order with code Hairlossnew, and next-day discreet delivery is available across the UK.

Preventing and Managing Medical Conditions That Cause Hair Loss in Men

While genetic predisposition and autoimmune disease cannot be prevented, optimising general health reduces the risk of nutritional and hormonal hair loss. Maintain a balanced diet rich in iron, zinc, biotin, and vitamin D; consider annual blood tests if you have a family history of thyroid disease or anaemia. Manage chronic conditions such as diabetes and inflammatory disorders with your GP's guidance, and avoid crash diets or extreme weight loss, which can trigger telogen effluvium [1].

If you are already being treated for a medical condition that causes hair loss in men, follow your clinician's advice on medication adherence and monitoring. Hair regrowth is often slow—visible improvement may take three to six months—and patience is essential. For pattern baldness unrelated to systemic disease, early intervention with finasteride or minoxidil offers the best chance of preserving existing hair and achieving modest regrowth [4].

• Eat a nutrient-rich diet with adequate iron, vitamin D, and protein
• Arrange regular blood tests if you have risk factors for thyroid or autoimmune disease
• Manage chronic health conditions under GP or specialist supervision
• Start evidence-based hair loss treatment early for male pattern baldness
• Avoid crash diets and extreme stress, which can trigger telogen effluvium

Scientific references

1. Malkud, S. (2015). Telogen effluvium: A review. Journal of Clinical and Diagnostic Research, 9(9), WE01–WE03. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4606321/ [accessed 28 October 2026]
2. Kaufman, K. D., Olsen, E. A., Whiting, D., et al. (1998). Finasteride in the treatment of men with androgenetic alopecia. Journal of the American Academy of Dermatology, 39(4), 578–589. https://pubmed.ncbi.nlm.nih.gov/9777765/ [accessed 28 October 2026]
3. Rushton, D. H. (2002). Nutritional factors and hair loss. Clinical and Experimental Dermatology, 27(5), 396–404. https://pubmed.ncbi.nlm.nih.gov/12190640/ [accessed 28 October 2026]
4. Gupta, A. K., & Foley, K. A. (2017). 5% minoxidil: Treatment for male pattern baldness. Skin Therapy Letter, 22(5), 5–7. https://pubmed.ncbi.nlm.nih.gov/29234768/ [accessed 28 October 2026]
5. NHS. (2026). Hair loss. https://www.nhs.uk/conditions/hair-loss/ [accessed 28 October 2026]
6. NHS. (2026). Finasteride: a medicine to treat an enlarged prostate and male pattern baldness. https://www.nhs.uk/medicines/finasteride/ [accessed 28 October 2026]