Whether the lost hair can still grow needs to be judged according to the state of the scalp hair follicles. Hair growth is divided into growth phase, regression and resting phase, in the regression and resting phase after the hair will begin to fall out, but after the hair loss, if the hair follicles are not damaged, until the growth phase will have new hair growth, so hair loss under normal circumstances is not to worry about. However, it should be noted that some pathological factors lead to hair loss, such as androgenetic alopecia, traumatic alopecia, infectious alopecia need to be treated in order to recover; if there is inflammation in the head, resulting in serious damage to the scalp follicles, permanent alopecia will be formed, and the lost hair can not be grown out. When patients have abnormal hair loss, they need to go to the hospital in time for examination and diagnosis, and after clarifying the cause of the disease, they should under the guidance of professional doctors carry out targeted treatment in combination with their personal situation, so as to avoid delaying the condition and aggravating the symptoms, which will lead to serious adverse consequences.