Hair loss causes can be triggered by several factors, which can include inherited genetics, disease, stress, medicines, injury, ageing or lack of proper hair care. A detailed look into these cases reveals that. Inherited Hair Loss: Genetics is one of the leading causes of hair loss, which is inherited either from one or both of your parents. This type of hair loss is called male-pattern hair loss, female-pattern hair loss or androgenetic alopecia. Mental, emotional or physical stress: Recent surgery, illness or high fever can also cause substantial hair loss. In most cases, though, your hair will grow back after a few months. Age: As we grow older, our hair tends to break far more easily, and our hair follicles do not grow as much hair to replace the loss.