Why do smokers cough when they are deprived of cigarettes for too many hours?

Smokers often experience coughing when deprived of cigarettes due to the body's withdrawal from nicotine and the accumulation of mucus in the airways. Smoking irritates the respiratory system, leading to increased mucus production, and when a smoker stops, the body attempts to clear this buildup, resulting in a cough. Additionally, the absence of nicotine can trigger the respiratory system to become more active, further exacerbating the cough reflex.