Hair loss is not caused by the number of times you wash your hair, or the soap you use. It is not caused by clogged pours, or oily scalp.
Hair loss is an inherited trait.
Not, as widely believed, from your mother's side, but from both your mother's and father's family genes. Not only hair loss, but thickness, color, texture, and growth patterns. How genes work is not completely understood. However, how hair loss and male pattern baldness works is understood. It starts at puberty, testosterone levels increase, this gives males their gender characteristics.