Critical hyperglycemia can be controlled by diet therapy as well as exercise therapy. 1. Diet therapy: For patients with hyperglycemia, the daily diet structure should control the total calories and choose more low-carbohydrate, low-sugar and high dietary fiber foods, such as coarse grains, beans, vegetables, etc., which is conducive to maintaining the stability of blood glucose. 2. Exercise therapy: Exercise can improve insulin sensitivity and help lower blood glucose, so it is recommended that patients with high blood glucose should have at least 150 minutes of moderate-intensity exercise every week to control their weight. If the patient’s blood sugar continues to rise, it is recommended to go to the hospital in time to improve the examination and follow the doctor’s instructions for medication.