After 72 hours breathing feels easier as your bronchial tubes have started to relax, and your energy levels are increasing.
After 10 weeks the blood will be pumping through to your heart and muscles much better because your circulation will have improved.
After 1 year, your risk of heart attack will have halved compared to a smoker's.
For the majority of smokers, smoking starts at a young age through a conscious decision, but after a while it becomes just another addictive habit.
This habit is hard to break by willpower alone, because it has become deeply embedded in your subconscious mind. So you begin to associate smoking with certain activities and to adopt it as a part of who you are.
As soon as this happens, the choice to smoke is no longer within your conscious control and therefore, deciding to give up it is extremely difficult.