The actual bloodstream of the plantar warts can be absorbed in 5 to 7 days. If the bloodstream is big or not healed for more than 7 days, the liquid inside the bloodstream can be extracted under the guidance of professional doctors to promote the wound healing. 1. The black blood bubble after the plantar warts cryotherapy is a normal phenomenon, usually 5~7 days can be absorbed to heal, the blood bubble is smaller usually do not need special treatment, the body will be absorbed on its own. 2. If the blood blisters are large or not healed for more than 7 days, you need to use a disposable syringe to draw out the blisters after local disinfection, and follow the doctor’s instructions to apply antibiotic ointment such as mupirocin ointment to prevent infection. Avoid touching the wound with water and avoid excessive activities during the treatment period. It is recommended that the appearance of large black blood blisters do not heal in time to seek medical attention, by a professional doctor for aseptic treatment, do not blindly operate on their own.