Diabetes mellitus blood sugar can not be lowered, may be due to poor dietary control, not enough exercise, not reasonable use of hypoglycemic drugs and other reasons, it is recommended to consult a doctor in a timely manner. 1. Poor dietary control: Dietary treatment is the foundation of diabetes treatment. If patients do not have strict dietary control and their daily intake exceeds the daily intake standard, or if they do not maintain a low-salt, low-fat and low-sugar diet and eat foods with high sugar content, such as cakes and ice cream, etc., it may lead to the failure of patients to lower their blood glucose. 2. Insufficient exercise: diabetic patients can carry out moderate aerobic exercise under the guidance of doctors. If the patient’s exercise is not up to standard, it may also lead to poor blood sugar control. 3. No reasonable use of hypoglycemic drugs: Insufficient dosage of drugs or incorrect hypoglycemic program may lead to the patient’s blood sugar not coming down. It is recommended that diabetic patients whose blood glucose value has not been lowered should consult the attending physician in time and follow the doctor’s instructions for standardized treatment.