You can’t. First, nicotine stimulates adrenaline secretion, which is a hormone that excites sympathetic nerves and raises blood sugar, causing tachycardia, increased blood pressure and blood sugar fluctuations, which is very detrimental to patients. Secondly, incomplete combustion of tobacco leaves will produce toxic and harmful substances, mainly nicotine, carbon monoxide, tar, etc., which can impair the function of the pancreas, and its function of insulin secretion will be weakened. In addition, smoking raises LDL cholesterol and also makes it easy to oxidize, and oxidized LDL is the main substance that damages blood vessels. The greatest threat to diabetic patients is vasculopathy, especially obstructive vasculopathy. Diabetic patients often do not smooth the inner wall of the blood vessels, blood viscosity, red blood cell deformation capacity is reduced, it is easy to occur vascular obstruction. Smoking will cause vasoconstriction, wall thickening, lumen narrowing, slow blood flow, vascular spasm, increased blood viscosity, causing tissue ischemia and hypoxia, especially prone to the formation of thrombosis blocking blood vessels. Blocking the cerebral vessels is cerebral thrombosis or lacunar cerebral infarction, blocking the heart vessels is angina pectoris or myocardial infarction, blocking the lower limb vessels is lower limb ischemia or even necrosis, blocking the kidney or fundus vessels, it will form diabetic nephropathy or retinopathy, with serious consequences. Remind the diabetic patients who smoke: quit smoking, can prevent the development of diabetes and its complications, can reduce a lot of harm to the human body.