Hair Thinning Causes in Men

Hair thinning isn’t always about “going bald” — but it’s almost always a sign your follicles need attention.
Knowing the cause is the first step toward stopping and reversing the process.

1. Androgenetic Alopecia (Male Pattern Baldness)

The #1 cause of hair thinning in men.

Caused by genetic sensitivity to DHT (dihydrotestosterone)
DHT gradually shrinks hair follicles (miniaturization)
Common patterns: receding hairline, thinning crown, or both

Fact: Affects up to 50% of men by age 50 — but can start in your 20s.

What to Do: Treatments like finasteride and minoxidil can slow, stop, and even reverse progression.

Triggered by physical or emotional stress: illness, surgery, major life events, crash dieting
Pushes more hairs than usual into the shedding (telogen) phase
Usually temporary — growth resumes in 3–6 months once the trigger is removed

What to Do: Identify and address the stressor; support hair health with nutrition and gentle care.

3. Nutritional Deficiencies

Certain nutrient gaps can weaken hair:

Iron (especially ferritin levels) — essential for hair growth
Vitamin D — linked to follicle cycling
Zinc — supports protein synthesis
Protein — hair is 90% keratin, a protein

What to Do: Blood tests can confirm deficiencies; targeted supplementation can help restore density.

4. Hormonal Changes

Thyroid disorders (hypo- or hyperthyroidism) can disrupt the hair cycle
Low testosterone or other hormonal imbalances may also contribute

What to Do: Consult a doctor for blood work; treat the underlying condition.

5. Scalp Conditions

Seborrheic dermatitis (dandruff)
Psoriasis
Folliculitis (inflammation/infection of follicles)

Chronic inflammation can weaken follicles and lead to miniaturization.

What to Do: Use medicated shampoos (ketoconazole, zinc pyrithione) and treat flare-ups promptly.

6. Overstyling & Physical Damage

Excessive heat styling
Tight hairstyles (man buns, braids — traction alopecia)
Harsh chemical treatments (bleach, perms)

Over time, these stressors can cause permanent follicle damage.

What to Do: Limit high-heat tools, avoid constant tension styles, and use heat protectants.

7. Medications

Some prescription drugs list hair thinning as a side effect:

Blood thinners
Certain antidepressants
Acne medications (high-dose vitamin A)

What to Do: Never stop a medication without your doctor’s advice — but ask about alternatives.

8. Aging

Even without male pattern baldness, hair naturally becomes:

Thinner in diameter
Slower to grow
Less pigmented (graying)

What to Do: Maintain scalp health, use thickening shampoos, and consider volumizing cuts.

9. When to See a Doctor

See a dermatologist or trichologist if:

Thinning is sudden or patchy
You notice excessive shedding in the shower or pillow
There’s redness, itching, or pain on the scalp

Early diagnosis = better treatment outcomes.

Bottom Line:
Hair thinning can be caused by genetics, health issues, lifestyle, or a combination.
Identifying your cause early is the key to slowing or reversing it.

Next Step: Explore our Finasteride Guide and Minoxidil Guide to learn about clinically proven treatments.