Flat warts are benign organisms caused by human papillomavirus (HPV) infection of the skin and mucous membranes. Generally, when flat warts appear to be localized redness, shrinking and drying up, shedding and fading, it means that flat warts have signs of improvement. In general, flat warts before the improvement of the basal part of the skin lesions red, warts can gradually become smaller, shrinkage, with the passage of time, warts can be shed, subside, until the warts disappeared. Flat warts after different treatments, the improvement process varies, if the frozen treatment, warts can show necrosis, shedding, healing, and laser treatment, can show necrosis, shedding, repair. The patient of flat warts should pay attention to avoid scratching flat warts warts and normal skin, to avoid the virus from scratching after the skin breaks planted, grow new warts. Flat warts patients are advised to go to the hospital in time, under the guidance of the doctor for professional treatment.