Forty-year-old gum recession may be a normal physiological phenomenon, may also be periodontal disease and other causes. 1. Physiological phenomenon: usually in middle age, after forty years old, with the growth of age, the gums will appear physiological shrinkage, is a physiological phenomenon, if not accompanied by other discomforts, usually do not have to deal with. 2. Periodontal disease: forty-year-old gum recession may be caused by periodontal disease, periodontal disease is usually not pay attention to oral hygiene, nutritional elements and long-term use of drugs such as phenytoin sodium. Patients will also have bleeding gums, loose teeth, shifting, chewing weakness, pain and other symptoms, and in severe cases, there will be tooth loss. Forty-year-old patients with gum recession, accompanied by other symptoms of discomfort, it is recommended to go to the hospital in a timely manner, under the guidance of the doctor to clarify the cause of the disease and then treatment.