Fess& septoplasty 7 days ago, been told stop smoking for 4 weeks. what will exactly happen if i smoke now? scar tissue, bleeding etc, please explain.

May delay healing: Cigarettes damage the cilia in the lining used to clear the mucus and clamp down the small vessels used in the healing process so that healing may be delayed. I do lots of sinus surgery even in smokers and don't ask them to quit and still get good results even though healing may be slower. I would tell you to stop smoking more for the heart and lung problems, and cancer risk.

Self defeating: why?: Smoking introduces nicotine which causes constriction of blood vessels while the carbon monoxide steals the necessary oxygen from the hemoglobin. Both delay healing and increase compcations such as infection. Smoking may lead to coughing which causes increased venous pressure and bleeding. It increases the chance of developing multiple cancers including lung stomach & other organs. Reason enough?!