Excessive Hair Loss (Alopecia): Causes, Evaluation, and Treatment

Step 1 - Identify the Type and Cause

Common Causes

Step 2 - When to See a Doctor

• Sudden or rapid hair loss
• Patchy bald areas
• Hair loss accompanied by fatigue, weight changes, or skin changes (could suggest thyroid disease)
• Hair loss with scalp redness, scaling, or itching (infection or inflammatory condition)
• A family history of early baldness + you want to start treatment early

• Blood tests: thyroid function (TSH), ferritin/iron, complete blood count, zinc, hormones (in women: androgens, prolactin)
• Scalp dermoscopy or biopsy if diagnosis is unclear

Step 3 - Treatment Options (by Cause)

For Androgenetic Alopecia (Pattern Baldness) - Most Common

• Minoxidil (Rogaine) - The only FDA-approved topical treatment for both men and women. Available OTC as 2% or 5% solution, or 5% foam. Increases follicle size and extends the growth phase (anagen). Low-dose oral minoxidil is now also used when topical is poorly tolerated or ineffective. - Cummings Otolaryngology, p. 445
• Finasteride (Propecia) - Oral pill for men. Inhibits the enzyme 5-alpha-reductase, which converts testosterone to DHT (the main driver of follicle miniaturization). Considered the gold standard for male pattern hair loss. Note: not approved for women; pregnant women should avoid contact with it.
• Dutasteride - More potent 5-alpha-reductase inhibitor, used off-label in men.
• Spironolactone - Anti-androgen used in women with hormonal hair loss.

• Platelet-Rich Plasma (PRP) - Injections of concentrated growth factors from your own blood into the scalp; stimulates follicles. Growing evidence for efficacy.
• Low-level laser therapy (LLLT) - FDA-cleared devices (combs, helmets). Modest benefit, useful as add-on.
• Hair transplantation (FUE/FUT) - Surgical grafting of follicles from the donor zone to bald areas. Best for stable, established hair loss with adequate donor density. Highly effective but permanent planning is needed to account for future loss. - Cummings Otolaryngology, p. 447

For Telogen Effluvium

• Usually self-limiting - resolves once the underlying trigger is removed.
• Treat the root cause (manage stress, correct nutritional deficiencies, adjust medications if possible).
• Topical minoxidil may help speed recovery.

For Alopecia Areata

• High-potency topical corticosteroids - first-line.
• Intralesional corticosteroid injections for localized patches.
• JAK inhibitors (baricitinib, ritlecitinib) - newer FDA-approved oral medications for severe alopecia areata; highly effective but require monitoring.

For Nutritional Deficiencies

• Iron supplementation if ferritin is low (aim ferritin > 40-70 mcg/L for hair health).
• Zinc and biotin if deficient (note: biotin supplements only help if you are actually deficient).
• Adequate dietary protein.

For Thyroid-Related Hair Loss

• Treating the underlying thyroid disorder usually reverses hair loss over several months.

For Traction Alopecia

• Stop the offending hairstyle early - follicles can recover if caught before scarring occurs.

For Fungal (Tinea Capitis)

• Oral antifungal therapy (griseofulvin, terbinafine).

Step 4 - Lifestyle Measures (For Everyone)

• Avoid harsh chemical treatments, excessive heat styling, and tight hairstyles.
• Eat a balanced diet with adequate protein, iron, and vitamins.
• Manage chronic stress (shown to trigger telogen effluvium).
• Be gentle when washing and brushing hair.

What's New (2025-2026)

• JAK inhibitors (ritlecitinib, baricitinib) have transformed treatment for alopecia areata, offering strong regrowth even in severe cases per recent systematic reviews and trials.
• PP405 (a topical follicle stem cell activator) showed promising Phase II results and is advancing to Phase III in 2026, per Healthline's 2026 treatment review.
• Low-dose oral minoxidil is increasingly used as an alternative to topical for various causes of hair loss.