Diabetic patients smoking has an impact, smoking will not only affect blood sugar stability, but also affect the vascular contractility. 1. Impact on blood sugar stability: smoking can stimulate the body’s sympathetic nerves, thus causing significant fluctuations in blood sugar and difficult to control. Therefore, long-term smoking is not conducive to diabetic patients’ blood sugar control, so it is recommended to quit smoking when suffering from diabetes. 2. Affecting vascular constriction: Cigarettes contain substances, such as nicotine, that may cause vascular constriction, which not only affects blood pressure, but also leads to vascular diseases, such as coronary heart disease and atherosclerosis and other diabetic macrovascular lesions, diabetic retinopathy, diabetic nephropathy, and other diabetic microvascular lesions, and so on. Therefore, diabetic patients should do their best to quit smoking to reduce the occurrence of chronic complications of diabetes, while diabetes is recommended to be treated under the guidance of a doctor.