Causes of Hair Loss

Hair loss can have many causes and is generally divided into hereditary and acquired factors. Acquired factors include poor hair care, stress, illnesses, nutritional deficiencies, hormonal changes and the side effects of certain medications. Each factor can weaken the hair through a different mechanism.

Hair Structure and Nature

Hair is mainly made of a structural protein called keratin. In humans, scalp hair has both protective and aesthetic functions. The human body has approximately five million hairs, while the scalp contains around 100,000 to 150,000 hair strands.

The shape, thickness and color of hair are influenced by genetics. Hair color depends on the amount of melanin in the hair shaft, while the condition of the scalp affects oiliness, dryness and hydration.

Hair Structure

Hair consists of three main parts:

• Hair shaft: the visible part outside the skin

• Hair root: the part located beneath the skin

• Hair follicle: a tunnel-shaped structure that surrounds the root and receives nutrients through blood vessels

The hair shaft contains three layers:

• Medulla: the soft central layer

• Cortex: the middle layer containing most of the melanin

• Cuticle: the outer protective layer that protects the hair from mechanical and environmental damage

Hair Growth Cycle

Hair grows in three main phases:

Anagen Phase

This is the active growth phase and usually lasts between three and five years. Most scalp hairs remain in this phase.

Catagen Phase

This transitional phase lasts approximately 10 days. Hair growth slows down and the follicle begins to shrink.

Telogen Phase

This is the resting phase and may last up to three months. Hair growth stops and the old strand eventually falls out as a new strand begins to develop.

Losing approximately 50 to 100 hairs per day is considered normal.

Abnormal Hair Loss

Hair loss becomes abnormal when the number of shed hairs is greater than the number of newly growing hairs. Identifying the underlying cause is essential for choosing the appropriate treatment.

Androgenetic Alopecia

Androgenetic alopecia is the most common form of hair loss and has a hereditary basis. It is associated with androgen hormones, especially testosterone and dihydrotestosterone.

Male Pattern Hair Loss

In men, hereditary hair loss usually begins at the temples and frontal hairline or at the crown. It may gradually affect the entire upper part of the scalp.

Female Pattern Hair Loss

In women, hereditary hair loss usually appears as gradual thinning along the central part of the scalp. Hormonal changes and reduced estrogen and progesterone levels may worsen the condition.

Telogen Effluvium

Telogen effluvium occurs when a large number of hairs enter the resting phase prematurely. Fever, thyroid disorders, iron or vitamin B deficiencies, stress, anesthesia and certain medications may trigger this condition. Hair growth often improves after the underlying cause is treated.

Anagen Effluvium

Anagen effluvium is commonly caused by medications, especially chemotherapy drugs. These medications affect actively growing hair cells. Hair usually begins to grow again after treatment ends.

Alopecia Areata

Alopecia areata is an autoimmune condition in which the immune system attacks the hair follicles. Hair loss usually appears suddenly in small, round patches and may also affect the eyebrows, eyelashes and facial hair.

Tinea Capitis

Tinea capitis is a contagious fungal infection that is more common in children. Symptoms may include patchy hair loss, itching, redness, inflammation, mild fever and swollen lymph nodes. It is usually treated with antifungal medication.

Scarring Alopecia

Scarring alopecia is caused by severe inflammation that damages the hair follicles and replaces them with scar tissue. Hair regrowth may be limited or impossible in affected areas.

Lichen Planopilaris

Lichen planopilaris is a rare inflammatory condition that affects the scalp and may cause gradual, patchy hair loss.

Discoid Lupus Erythematosus

This autoimmune skin condition can cause inflammation, sores and scarring on the scalp. Hair may not grow back in areas where permanent scarring has occurred.

Folliculitis Decalvans

Folliculitis decalvans is an inflammatory disorder that damages the hair follicles and may cause redness, swelling and pustules. Hair loss can sometimes be permanent.

Dissecting Cellulitis of the Scalp

This rare condition may cause inflammatory nodules, scarring and destruction of the hair follicles. It requires specialist medical care.

Frontal Fibrosing Alopecia

Frontal fibrosing alopecia usually progresses slowly but continuously. It often begins at the frontal hairline and temples and may also affect the eyebrows.

Loose Anagen Syndrome

This condition is more common in children. The hair root is not firmly attached to the follicle, so the hair can be pulled out easily.

Trichotillomania

Trichotillomania is a psychological condition in which a person repeatedly pulls out their own hair and has difficulty stopping. Treatment usually involves psychological or psychiatric support.

Tight hairstyles, constant traction and heavy braiding can also damage the roots and contribute to hair loss. Severe stress or emotional shock may cause temporary and sudden shedding.

Conclusion

The type and cause of hair loss should first be evaluated by a doctor or hair specialist. After diagnosis, an appropriate treatment plan can be selected. Regular hair care, a balanced diet, stress management and the use of suitable professional products may help maintain and strengthen hair health.