Endodontic treatment is suitable for patients of any age, and different treatment difficulties may exist in different age groups during treatment. There are also no absolute contraindications to endodontic treatment, but disabled and frail patients often find it difficult to withstand the complex and prolonged treatment process. The following groups of people should then have a detailed medical history and treatment plans should be developed according to their specific conditions. Patients with cardiovascular disease: Endodontic treatment for patients with severe cardiovascular disease should be handled after consultation with a cardiovascular specialist, with attention to relieving mental stress, shortening the consultation time, and controlling pain and anxiety during treatment. For patients with rheumatic heart disease, congenital heart disease or who have had heart valve replacement surgery, infective endocarditis caused by root canal treatment should be prevented. Patients who have had a myocardial infarction within the last 6 months are not suitable for endodontic treatment. Patients with hemorrhagic disease: Patients with hemorrhagic disease should undergo blood tests and consult with an internist before endodontic treatment. Be prepared to control bleeding during treatment such as placement of rubber barrier clips and live pulp extraction. Antifibrinolytic treatment should be performed before root canal surgery. Diabetic patients: To prevent acute endodontic infection from affecting the control of diabetic patients, antibiotics should be prevented before endodontic treatment and to avoid prolonged endodontic treatment that may affect the patient’s insulin therapy and meal time. For patients with severe diabetes, care should be taken to prevent the occurrence of insulin shock or diabetic coma. Patients with cancer: Take a medical history to understand the cancer patient’s condition and decide which treatment to use. Simple and easy methods can be used to relieve patients’ symptoms, improve chewing ability and improve mental status. Head and neck tumor patients are prone to rampant caries (a kind of acute caries) after radiotherapy and quickly develop into pulp disease or periapical disease, so endodontic treatment should be chosen to preserve the affected teeth and improve the patient’s quality of life. AIDS patients: AIDS is not a contraindication to endodontic treatment, and strict control measures should be taken to prevent cross-infection when treating AIDS patients. Pregnant women: Patients should pay attention to endodontic treatment during pregnancy, control pain and infection, and suspend root canal surgery. Allergic people: For highly allergic patients, antihistamines can be used before endodontic treatment to prevent allergic reactions.