Although diabetes is a chronic disease that is incurable, it is not a terminal disease, and studies have shown that long-term control of blood sugar to meet the standard, the life expectancy of diabetics and normal people is the same. Generally, patients with diabetes at the age of 40 are in good condition and have relatively few comorbidities, so they should have a correct understanding of diabetes, establish a correct view of the disease, be positive and optimistic, go to a regular medical institution as early as possible, get a standardized and reasonable glucose-lowering treatment plan under the guidance of a specialist, and regularly monitor their blood glucose, eat and live healthily, exercise in moderation in their future lives, and quit bad habits to control their blood glucose. In addition, if you can stop the bad habits and control your blood sugar for a long time, you can effectively prevent and delay the occurrence of complications. However, if you have a long history of diabetes at the age of 40, and your long-term blood sugar is not well controlled, and you have serious complications of diabetes such as diabetic nephropathy, diabetic retinopathy, diabetic foot, or even serious cardiovascular and cerebrovascular accidents, your life expectancy will be shortened, and your life may be in danger at any time. To sum up, generally speaking, how long you can live with diabetes at the age of 40 is closely related to the control of your blood sugar and the severity of complications.