It is normal that there may still be pain on the second day of tooth extraction. The degree of pain after tooth extraction varies from patient to patient. Some patients experience mild pain and do not need special treatment, while some patients have severe pain and need to take oral pain medication under the guidance of the doctor. The reason for the presence of pain on the second day of tooth extraction is mainly the existence of trauma to the local gum and alveolar bone, and the local tissue damage will stimulate the nerve endings, thus causing pain; complex tooth extraction also requires operations such as cutting soft tissue, separating mucoperiosteal flap and grinding away bone, thus destroying the tissue integrity and making the trauma deep and large, resulting in swelling and pain of the trauma and jaw face, and possibly fever and soreness of the whole body. The day after tooth extraction, the blood clot in the alveolar sockets is not stable and easily loosens and bleeds. Eating too hard and too hot food may easily cause the blood clot to loosen and fall off from the tooth extraction wound, so a liquid diet such as thin gruel, vegetable soup and milk in a warm and cool state should be given priority.