A friend just asked me which one to treat first, high blood sugar and tonsillitis? Another diabetic patient, who had enteritis a few days ago, stopped his insulin to treat the enteritis and almost had a big problem. Therefore, I would like to talk about the common sense of health care during our diabetic patients’ illness. During illness, mental tension and stress can raise blood sugar; irregular diet and exercise can also cause blood sugar to rise. Therefore, during illness, first of all, we should take medication as usual, and if we inject insulin, we should continue to inject it without stopping; secondly, we should ensure sufficient water and nutrition intake during illness, and if we have loss of appetite or nausea and vomiting, we should eat some easy-to-digest food; thirdly, we should monitor blood sugar more diligently than usual; fourthly, we should check urine to see if there are ketone bodies. If there is difficulty in breathing, change of mind, inability to eat, inability to drink, fever for more than 24 hours, strong positive urine ketone body, severe nausea and vomiting, severe diarrhea, etc., you should go to the hospital quickly and do not delay the condition.