The plasters need to be replaced in 12-24 hours, the exact time varies from person to person. The main component of plasters is usually blood-activating and pain-relieving drugs, which can activate blood stasis, promote circulation, reduce swelling and pain, etc. They are often used for patients with soft tissue injuries or back and leg pain, including bone and joint injuries, myofascial injuries, etc. Usually, the plaster can be applied for a maximum of 24 hours. After 24 hours, the efficacy of the plaster is significantly reduced, which may affect the breathing and permeability of the patient’s skin, leading to skin allergy, rash and, in serious cases, tissue inflammation, so the plaster needs to be replaced. If the patient’s skin is tender, the restriction time should be shortened accordingly. Therefore, patients need to pay attention to timely replacement of ointment every day, and a continuous medication for 5-7 days for better results. Infants, pregnant women and patients who are allergic to the creams should avoid using them.