Hot and painful shoulder ointment may be caused by the following reasons: First, it may be due to an open wound on the part of the shoulder where the ointment is applied. For example, if there is an inconspicuous skin injury here, if the plaster is applied again, it may stimulate the sensory nerves of the skin and cause the patient to have very obvious pain; second, it may be caused by an allergic reaction to the skin here. Some patients may have allergic reactions to certain ingredients in the plaster, and then after applying the plaster, there will be very obvious pain, itchiness or swelling in the part that touches the plaster; third, it may be caused by the drug stimulation of the plaster itself. Some ointments contain some very strong stimulating drugs, such as tincture of chili pepper or Chuanwu, Cao Wu, Tennantine and other drugs. When the cream is applied topically, it will cause a certain amount of stimulation to the patient, which will more or less produce the above-mentioned feeling. After the above symptoms appear, the patient must remove the cream as soon as possible, and then ask the relevant doctor to see, adjust the treatment plan.