Never smoked, but both parents did. Dad was a pack a day smoker, mom would get 2-3 days out of a pack. Dad started in 1942 when he went in the Army. Mom didn't smoke until she married dad in 1952. They both quit cold turkey in 1984, but the damage was already done and they ended up paying for it late in life. They both beat other forms of cancer, neither had lung cancer. But both suffered from respiratory problems and were on O2 24 hours a day during their last years.
Their DR explained to me that young healthy adults rarely use more than 1/2 their lung capacity. You can damage up to 1/2 the lungs and not see any decline when young. But as you age you naturally lose lung capacity. Combine that natural loss with the damage done by smoking when young and you'll struggle to breathe as you age. And it is worse for women since their lungs are smaller to begin with.
