The most serious hair loss in autumn may be due to physiological factors, malnutrition, endocrine diseases, iron deficiency anemia, androgenetic alopecia, etc.. 1. Physiological factors: nervousness, stress, staying up late and so on can cause hair loss, which can be improved soon after rest and regulation. In addition, the dry climate in the fall, dry scalp and poor blood circulation may also aggravate hair loss. 2. Malnutrition: When there is no balanced diet or insufficient nutrient intake in the body, the hair follicles cannot be provided with nutrients, and hair thinning and hair loss will increase. 3. Endocrine diseases: hypothyroidism or hyperthyroidism, hypothyroidism or hypopituitarism, adrenal tumors, etc. can cause hair loss. 4. Iron deficiency anemia: patients with anemia have insufficient nutrients for hair follicles and hairs, which can lead to dryness, yellowing, hair loss and other symptoms. 5. Androgenetic alopecia: Hair loss caused by increased levels of androgen is genetically related, with much hair loss on the top of the head, thinning hair and receding hairline. It is normal to lose about 70~100 hairs per day. If hair loss is serious and not relieved, or accompanied by other symptoms, you should go to the hospital in time to get a clear cause and then give targeted treatment.