There are more reasons for hair loss, and you need to understand the hair growth cycle, which can generally be divided into three phases, namely the growth phase, resting phase and recession. Therefore, every day hair growth and shedding, called physiological hair loss, generally do not need treatment. Pathologic alopecia is commonly seen, for example, as patchy baldness, which is a type of limited patchy baldness that occurs suddenly on the head, also known as round baldness. The scalp at the place of hair loss is normal, no inflammation, no self-conscious symptoms, and can be relieved and recur on its own. Many patients with patchy baldness can be cured without treatment, and most of them can grow hair after treatment. Seborrheic alopecia, also known as male pattern baldness, occurs in young and middle-aged people, often with a family history of the disease, patients with androgen imbalance, the scalp to the normal or high androgen, resulting in a powerful amplification effect, interfering with the follicle sebaceous gland metabolism, the manifestation of alopecia and sebaceous overflow increase. Patients often due to stay up late, often eat spicy stimulating and greasy food and sweets due to unsatisfactory treatment, it is difficult to grow hair. Currently, oral Bupropion and topical Minoxidil solution can achieve relatively good results. Hair loss during pregnancy and post-pregnancy hair loss, mostly seen after the end of pregnancy, often sleep deprivation and hormone level imbalance, generally can adjust hormone levels, pay attention to sleep, with anti-hair loss medication can be treated. Some patients are allergic to shampoos, hair dyes or oil baking agents, which leads to hair loss. If there are suspects, patients should immediately stop using allergenic shampoos, hair dyes, etc., and try to use mild shampoos.