Hair Loss Causes: Why Is Your Hair Falling Out?

Understanding Hair Loss: The Most Common Causes

Hair loss affects millions of people worldwide. While losing 50-100 hairs daily is perfectly normal, excessive hair loss can signal various underlying conditions. This guide explains the main causes and what you can do about them.

Androgenetic Alopecia (Pattern Hair Loss)

Androgenetic alopecia is by far the most common type of hair loss, affecting:

• Men: Up to 80% during their lifetime
• Women: About 40% after menopause

How Does Pattern Hair Loss Work?

The hormone DHT (Dihydrotestosterone) binds to receptors on hair follicles, causing them to miniaturize. Hairs gradually become thinner and shorter until the follicle no longer produces visible hair.

Male Pattern (Norwood Scale)

In men, hair loss typically begins at the temples and crown:

• Norwood 1-2: Slight recession at the temples
• Norwood 3-4: Noticeable receding hairline, thinning crown
• Norwood 5-7: Advanced hair loss, remaining hair forms a horseshoe pattern

Female Pattern (Ludwig Scale)

In women, hair loss typically manifests as diffuse thinning along the part:

• Ludwig I: Mild thinning along the centre part
• Ludwig II: Noticeably visible thinning
• Ludwig III: Near-complete hair loss on top of the scalp

Stress-Related Hair Loss

Telogen effluvium is the second most common form of hair loss. It occurs 2-3 months after a stressful event:

• Serious illness or surgery
• Chronic psychological stress
• Crash diets or significant weight loss
• Childbirth
• Bereavement

The good news: telogen effluvium is typically reversible. Once the stress source is removed, hair regrows within 6-12 months.

Nutritional Deficiencies

Certain nutrient deficiencies can cause or worsen hair loss:

Iron

Iron deficiency is a particularly common cause of hair loss in women. A ferritin level below 30 ng/ml can already trigger increased shedding.

Vitamin D

Vitamin D deficiency is widespread in Northern Europe and can disrupt the hair cycle. Studies show a link between low vitamin D levels and alopecia.

Biotin and Zinc

Biotin and zinc are essential for hair growth. Deficiency is rare but can occur with restricted diets.

Protein

Hair is 90% keratin (a protein). A protein-rich diet supports healthy hair growth.

Hormonal Causes

Thyroid Disorders

Both overactive and underactive thyroid can cause hair loss. Treating the underlying condition usually leads to improvement.

Hormonal Changes in Women

• Pregnancy/Breastfeeding: Postpartum hair loss is common and temporary
• Menopause: Declining estrogen levels can trigger hair loss
• PCOS: Polycystic ovary syndrome can cause androgen-related hair loss

Medication-Related Hair Loss

Certain medications can cause hair loss as a side effect:

• Blood thinners
• Blood pressure medications (beta-blockers)
• Antidepressants
• Chemotherapy (Anagen effluvium)
• Retinoids (Vitamin A derivatives)

Alopecia Areata (Spot Baldness)

Alopecia areata is an autoimmune condition where the immune system attacks hair follicles. Characteristics:

• Round, coin-sized bald patches
• Sudden onset
• Can begin at any age
• Hair regrows within one year in 80% of cases

When to See a Doctor

Consult a dermatologist if:

• Hair loss is sudden or occurs in clumps
• Bald patches become visible
• Hair loss is accompanied by itching or pain
• You lose significantly more hair than usual for several weeks
• Hair loss affects your quality of life

Conclusion

Hair loss has many possible causes. An accurate diagnosis is the first step toward the right treatment. While genetic hair loss can be treated with medication or hair transplantation, other forms are often reversible once the underlying cause is addressed.