It is autosomal dominant inheritance, and its genetic characteristics need to be expressed under the action of androgen.

2. Neuropathic alopecia

When mental stress is too great, hair loss tends to increase. Under the action of mental stress, the hair muscles of human body contract, the hair stands upright, the autonomic nerve or central nervous system function is disordered, the papillae of hair follicle changes, and malnutrition leads to the inhibition of hair growth function, and the hair enters the rest period, resulting in hair loss.

3. Endocrine alopecia

The growth of hair is influenced by many endocrine hormones, so when the endocrine is abnormal, it often causes alopecia diseases, such as postpartum and menopausal alopecia.

4. Nutritional alopecia

Hair is an external manifestation of physical condition. Malnutrition and abnormal metabolism will cause changes in hair quality and hair color, severe malnutrition and even diffuse alopecia.

5. Physical alopecia

Common physical factors leading to hair loss include mechanical stimulation and exposure to radioactive substances.

6. Chemical alopecia

Chemical factors can lead to hair discoloration and even hair loss.

7. Infectious alopecia

Infection of various pathogens is an important factor of hair diseases, mainly including bacteria, viruses, fungi, spirochetes, parasites and other infections.

8. symptomatic alopecia

Some systemic or local diseases may be accompanied by alopecia.

9. congenital alopecia

The hair caused by developmental defects is completely missing or sparse, and patients often have sparse and fine hair, or the hair is normal at birth and will not regenerate quickly, which can be divided into isolated defects and other deformities.

10. Seasonal alopecia

Generally, it is easy to lose hair in summer, because the high temperature in summer leads to the expansion of pores, and it is not easy to lose hair in autumn and winter, because the temperature drops and the pores are closed during this period.