A toothache in the afternoon is considered to be caused by dental caries, pulpitis, periodontitis and other diseases. 1. Dental caries: mainly under the influence of a variety of factors, mainly bacterial, the hard tissues of the dentin undergo chronic progressive destruction of a disease, which can lead to changes in the texture and color of the teeth, the shape of the defect, resulting in toothache and swelling and other discomforts. Especially if you don’t brush your teeth in time after lunch, the stimulation of food residue can aggravate the pain. 2. Pulpitis: It is an inflammatory disease that occurs in the pulp of the teeth, mainly caused by bacterial infection, which can lead to tooth pain and other phenomena. Since you are distracted by work and life during the day, you may feel pain once you are idle in the afternoon or evening. 3. Periodontitis: It is a chronic infectious disease of periodontal tissues caused by plaque biofilm, mainly caused by plaque, dental trauma and other factors, which can lead to toothache as well as bleeding gums and other symptoms. In the afternoon, the pain is more likely to be felt after eating. Toothache once in the afternoon may have a variety of reasons, it is recommended to seek medical attention in time, under the guidance of the doctor to clarify the cause and treatment.