Quitting smoking increases lung function

3-9 months after quitting smoking, coughs, wheezing and breathing problems improve as lung function increases by up to 10%.

Source: What happens when you quit? @ NHS Smokefree

Image by Challiyil Eswaramangalath Vipin from Chalakudy, India (cigarette.. like a cigarette in the rain) [CC-BY-SA-2.0], via Wikimedia Commons