You know all those advertisements that say "Stop smoking, and start repairing your lungs"? Well that's actually quite misleading because as you get older your lungs degrade in health (in terms of respiratory performance). This is normal for everyone who is 25 years or older.
Smoking causes your lungs to degrade at a faster rate and at the same time decreases your respiratory performance significantly. When you stop smoking at a particular age, your respiratory performance is at a much lower level than a person of the same age who has never smoked before, BUT your lungs will not heal or climb back to the normal level. Instead, they will continue to degrade at the same rate as the person who has never smoked before. It is declining slower, which is a good reason why you should quit, but it DOES not mean that your lungs are healing. The only difference is that the respiratory performance of your lungs is at a lower level than the person who hasn't smoked, and obviously it will be even lower if you stopped smoking at a later age.
This is a common misconception that people make. It is just a little piece of information but hopefully it can help your battle with smoking in some way. Best of luck.
