Can stress cause hair loss?

Yes. Severe stress triggers telogen effluvium — a condition where a large proportion of hairs simultaneously enter the resting phase. About 2–3 months later they shed en masse. Once the stress is resolved, hair typically regrows within 6–12 months.

Is hair loss permanent?

Androgenetic alopecia is progressive and permanent without intervention, but can be slowed with finasteride and minoxidil. Hair loss from stress, nutritional deficiencies, medications, or hormonal changes is typically reversible once the underlying cause is addressed.

📚 Guide Article

Why Is My Hair Falling Out? 12 Causes Explained

Q: What is the most common cause of hair loss?

In men, over 95% of hair loss is caused by androgenetic alopecia (male pattern baldness) — a genetic condition where DHT (dihydrotestosterone) miniaturises hair follicles over time. In women, hormonal changes (post-partum, menopause) and iron deficiency are most common.

Losing 50–100 hairs per day is normal. More than that means something's driving it. Here are the 12 proven causes of hair loss — and what you can do about each one.

✍️ AtlasMind AI Editorial 📅 27 February 2026 ⏱️ 8 min read

💡 Want the shortcut? Upload 3 photos to our free AI hair analysis tool and get your Norwood stage, loss speed, and likely cause category in 30 seconds — no consultation needed.

The 12 Causes at a Glance

Cause #1

Androgenetic Alopecia (Genetics)

Responsible for 95%+ of male hair loss. DHT shrinks hair follicles progressively.

Cause #2

DHT Sensitivity

Even without strong family history, some follicles are genetically hypersensitive to DHT.

Cause #3

Chronic Stress (Telogen Effluvium)

Stress pushes follicles into resting phase; en-masse shedding 2–3 months later.

Cause #4

Iron & Ferritin Deficiency

Most common reversible cause in women. Ferritin below 40 ng/mL is a red flag.

Cause #5

Thyroid Dysfunction

Both hypothyroidism and hyperthyroidism disrupt the hair growth cycle.

Cause #6

Hormonal Changes

Post-partum, menopause, PCOS — androgens shift relative to oestrogen.

Cause #7

Protein & Zinc Deficiency

Hair is ~95% keratin (protein). Insufficient protein directly causes shedding.

Cause #8

Medication Side Effects

Chemotherapy, blood thinners, some antidepressants, high-dose retinoids.

Cause #9

Physical Hair Damage

Excessive heat, chemical processing, traction alopecia from tight hairstyles.

Cause #10

Autoimmune (Alopecia Areata)

Immune system attacks hair follicles causing patchy or complete loss.

Cause #11

Scalp Infections

Tinea capitis (ringworm) or folliculitis can block hair growth in affected areas.

Cause #12

Ageing

Follicle miniaturisation accelerates after 50; growth phase shortens naturally.

1. Androgenetic Alopecia — The #1 Cause

In men, 85–95% of hair loss is androgenetic alopecia (AGA). This is a genetic condition where follicles in certain scalp zones carry androgen receptors that, when bound by DHT (dihydrotestosterone), trigger progressive miniaturisation.

The process: DHT shortens the anagen (growth) phase from years to months, extends the telogen (resting) phase, and gradually converts terminal hairs into vellus (fine, colourless) ones until the follicle closes entirely.

AGA follows the Norwood-Hamilton scale — 12 stages from full hair to complete crown and frontal baldness.

⚠️ Note: AGA cannot be fully stopped but can be significantly slowed with finasteride (blocks DHT production) and minoxidil (prolongs growth phase). Always consult a dermatologist before starting either medication.

2. Telogen Effluvium — Stress-Related Shedding

Physical or emotional stress, surgery, illness, childbirth, or crash dieting can push a large percentage of follicles into the telogen (resting) phase simultaneously. 2–3 months later, those follicles shed en masse.

Key point: The shedding happens after the stress, not during it. So if you're losing hair now, think back 2–3 months — what stressor occurred?

The good news: telogen effluvium is generally reversible. Once the trigger is removed, regrowth typically occurs within 6–12 months.

3. Nutritional Deficiencies

Hair growth demands substantial nutritional resources. Key deficiencies:

Iron/Ferritin: The most common reversible cause in women. Target ferritin above 40 ng/mL for optimal hair growth. Get a blood test — don't supplement blindly.
Protein: Hair is ~90% keratin. Low-protein diets or crash diets directly cause shedding within weeks.
Zinc: Critical for follicle repair and cell division. Deficiency causes brittle, easily shed hair.
Vitamin D: Vitamin D receptors regulate the hair cycle. Low levels correlate with increased shedding.
Biotin: Widely marketed but only effective in genuine biotin deficiency (rare). Supplements are unlikely to help unless you're deficient.

Which cause applies to you?

Upload 3 photos — our AI measures your loss speed, Norwood stage, and narrows down the likely cause category.

🔬 Free AI Hair Analysis

4. Hormonal Changes (Women)

Post-partum hair loss: High oestrogen during pregnancy prevents normal shedding. After delivery, oestrogen drops sharply and months of "banked" hairs shed simultaneously. Typically resolves spontaneously in 6–12 months.
Menopause: As oestrogen declines, androgens become relatively more dominant — follicles become DHT-sensitive.
PCOS: Elevated androgens cause alopecia in the female pattern (vertex thinning) and often also hirsutism.

Frequently Asked Questions

What is the most common cause of hair loss?

In men, androgenetic alopecia accounts for over 95% of cases — caused by genetic DHT sensitivity that miniaturises follicles over time. In women, hormonal changes (post-partum, menopause) and iron/ferritin deficiency are most common.

Can stress cause permanent hair loss?

Acute stress typically causes telogen effluvium — a temporary, reversible condition. However, chronic long-term stress may accelerate androgenetic alopecia in those with the genetic predisposition, effectively making it partially permanent.

Is hair loss from medications permanent?

Most medication-induced hair loss is reversible once the drug is stopped or replaced. Hair typically regrows within 3–6 months. Never stop prescribed medications without consulting your doctor.

How do I know which cause applies to me?

Our AI analysis tool compares your hair photos over time to measure loss speed and pattern — which helps narrow down the likely category. For a definitive diagnosis, consult a dermatologist or trichologist with blood test results.