Normal people lose hair every day, and if the number of hairs lost is less than 100 per day, there is usually nothing to worry about and it is normal. If the number of hairs lost by a woman far exceeds this range, it may be caused by baldness, androgenetic alopecia and polycystic ovary syndrome. 1. Patchy baldness: autoimmune, neuropsychiatric, genetic and endocrine factors can trigger patchy baldness, and patients will experience patchy hair loss on the scalp. 2. Androgenetic alopecia: Hereditary, androgenic and psychiatric factors may lead to androgenetic alopecia, which is characterized by a gradual decrease, thinning and loss of hair on the top of the forehead. 3. Polycystic Ovary Syndrome (PCOS): Heredity, environment and other factors may lead to polycystic ovary syndrome, which may cause menstrual disorders, female pattern baldness, hairiness and so on. There are many reasons that lead to severe hair loss in women. After eliminating physiological factors, patients are advised to seek medical examination to clarify the cause of the disease.