(1) Hereditary male pattern baldness:
Male pattern balding affects 50% of Caucasian men by age 50. The condition is less common in Asian men while starting much later in life. Men with family history of androgenetic hair loss have a higher risk of this condition. The progressive loss of hair is caused by increased in androgen production.
(2) Hormonal changes:
A sudden change in hormone levels during major stressful periods or after childbirth can cause significant hair loss. This normally occurs two or three months following the triggering event.
(3) Hair-pulling habits:
Certain individuals tend to pull their hair when they are in distressed while others may suffer from a psychological disorder known as trichotillomania where they have the compulsive urge to pull hair out of their body. Habitual hair pulling or twisting can cause breakage of hair or even scarring of the scalp.
(4) Underlying medical conditions and infections
Thyroid disease, inflammatory conditions (such as psoriasis, dermatitis and systemic lupus erythematosus) and infections (especially fungal infections) can cause significant hair fall.
(5) Dietary deficiency
The lack of protein, zinc or iron intake can lead to hair loss especially in serious cases of malnutrition.
(6) Inappropriate hair handling practice
Prolonged tight hairstyling practices such as braiding, wearing of tight hair accessories (i.e. hair clips and bands) and extreme combing can cause strain to the hair leading to gradual hair loss. Hair loss commonly occurs at the hair line. Exposing the hair to extreme heat, exposure to certain chemicals in shampoos or dyes can also cause hair fall.
(7) Medication side effects
Anticancer drugs, cardiovascular medications and hormonal contraceptives can speed up hair loss. Hair loss is generally reversible upon stopping of these drugs.
Some of these causes are reversible although any damage to the scalp that causes scarring can lead to permanent hair loss. If you are affected by hair loss, please see a dermatologist for proper evaluation and management.