Some patients told me during the consultation that they were very afraid of the operation and wondered whether they could have a cigarette before the operation to stabilize their emotions on the one hand and to have a calming effect on the other. It is common knowledge that smoking is harmful to health. I personally smoked when I was young, but I have quit now for the sake of my health. Is smoking harmful to surgery? How does it affect the surgery? Smoking is harmful to the human body mainly through the toxic alkaloids contained in tobacco smoke – nicotine and carbon monoxide (CO). Nicotine stresses the heart and increases oxygen consumption, while carbon monoxide impairs the ability to deliver oxygen to the heart. Smoking increases the risk of lung infections: Lung complications are the most common complication in surgical patients, and smoking is an independent risk factor for perioperative respiratory complications. Smoking can cause inflammatory changes in lung tissue, weakening the clearance function of the respiratory mucus-cilia transport system, and decreasing the sensitivity of the cough reflex, resulting in an increase in sputum, which cannot be discharged, increasing the risk of postoperative lung infection. Smoking causes delayed wound healing after surgery: nicotine stimulates the sympathetic nervous system to release catecholamines, causing peripheral vasoconstriction and lowering the tissue perfusion rate; carbon monoxide increases blood viscosity and inhibits the combination of hemoglobin and oxygen, which reduces the supply of blood and oxygen to the wound skin; and it destroys the production of collagen, which exacerbates the delay in wound healing. If you are having surgery to join blood vessels in microsurgery, your doctor will definitely tell you that you cannot smoke before the surgery and you are not allowed to smoke for a month after the surgery. This is because it can lead to hardening of the blood vessels, spasm of the blood vessels, etc., which will definitely have an effect on the outcome of the surgery. There are no strict rules or rigorous tests for minor surgeries, but from personal experience, it does have a slight effect. Overall, smoking is a bad habit, and I urge everyone to quit smoking as soon as possible to reduce the intake of nicotine, which is good for our health.