Hair loss has various causes. Whether it's a one-off or gradual process, it is often linked to excess sebum secretion as well as other factors such as stress, fatigue, hormonal or seasonal variations and heredity. There are two types of hair loss: Temporary (occasional) hair loss, which leads to a thinning of the hair fiber Permanent (chronic) hair loss, which is characterized by the progressive thinning of the hair fiber until it falls out completely.