Cigarette or tobacco smoking causes adverse effects on various systems of the body. What happens when you quit smoking? What happens to the adverse effects which smoking has caused? How reversible are they after quitting tobacco? This post discusses and answers these questions.

Smoking cuts at least 10 years of your life expectancy. One cigarette smoked reduces your life by 11 minutes. Very few smokers reach the age of 80 years.

All effects of cigarette or tobacco smoking are vastly enhanced if you have been smoking from childhood or adolescence. The addiction sets in very firmly in such cases and it becomes extremely difficult for the smoker to give up.

Beginning to smoke at an early age increases the number and severity of respiratory and cardiovascular complications.

According to a recent finding, reported by the Centers for Disease Control and Prevention (CDC), the incidence of teenage smoking has increased by nearly a third during the last six years.

This is due to the fact that teenagers incorrectly believe that they can quit smoking after a few years before any long-term effects set in.

Smoking cessation is very low among teenagers who started smoking so early on. It is less than 16 percent.

If you have been smoking occasionally, say one cigarette per day, and feel you are not vulnerable to the health implications of smoking, you are sadly mistaken.

Or, if you feel that you smoke “light” cigarettes and feel relatively “safer”, then you again believe in a myth. There is no such thing as a light cigarette. Light cigarettes are equally dangerous to health.

How reversible are the effects of smoking after quitting tobacco? 

However, if you have succeeded in quitting smoking, are the effects caused by smoking on the health of the body reversible? Can the health problems caused by smoking be reversed? The reversible prognosis of each smoking effect on the body varies and we discuss it below.

Life expectancy after quitting smoking

According to the New England Journal of Medicine, if you stop smoking before the age of 40 years, your risk of dying from smoke-related disease reduces by 90%. That is one smoking effect that can be considerably reversed.

The study also found that quitting tobacco at the age of 45 to 54 years increased their lifespan by about six years as compared to people who continued to smoke, while those who quit a little later age at 55 to 64 years of age gained only about four years of life.

According to Dr. Prabhat Jha, head of the Centre for Global Health Research at St. Michael’s Hospital in Toronto, giving up smoking earlier at the age of 30 years or even 40 years will give you a life expectancy equal to those who never smoked. You regain all those lost years.

That does not mean you can smoke till the age of 40 years. Smoking for all those years does add an element of risk of developing smoking complications.

Smoking-related mortality is similar, irrespective of gender. Women smokers face the same amount of risk of smoking-related diseases as men.

According to the National Institute of Health, the risk of dying from smoking-related diseases for past smokers remains high even years after quitting. However, the risks do come down though not entirely.

Effects of smoking cessation on the respiratory system

On giving up smoking completely, the inflammation in the lungs begins to recede and the cilia in the airways, which were paralyzed due to cigarette smoke, begin to move and clear the airways of mucus.

Lung function and breathing improve and consequently so do your physical capacity (stamina) and gym performance.

The risk of lung cancer, and cancers of the mouth, throat, bladder, cervix, and pancreas drops.

If you have developed chronic bronchitis (inflammation of the airways) it will start to recede. But, if the inflammation has led to scarring of the airway lining, then that will stay permanent.

Emphysema is a lung condition commonly seen among smokers. In this disease, smoking damages the walls of the air sacs located at the end of the bronchioles. These walls have small blood vessels running through them.

It is in the air sacs that the exchange of gases carbon dioxide and oxygen in the blood takes place. Due to the breakdown of the walls, the gaseous exchange becomes inefficient.

The damage caused by highly progressed chronic bronchitis and emphysema is permanent.

Chronic obstructive pulmonary disease (COPD) is a lung condition in which both chronic bronchitis and emphysema are present. This disease is progressive and quitting smoking does not reverse this condition. However, the progression of the condition may slow down.

A lot depends on the number of cigarettes the person has smoked and the number of years he has smoked.

This is referred to as the “pack years”, which refers to the number of packs every day multiplied by the number of years of smoking. A heavy smoker is defined as one who has 20 pack years to his credit.

The risk of lung-related disease is directly proportionate to the number of pack years. If you have a lot of pack years, say 30 and above, the risk will not come down to that of the nonsmoker. Even the lung function will not revert back to its original state.

If you are at an advanced age and have been smoking for 20 to 30 years, quitting smoking even then can have some leftover benefits.

Effect of smoking cessation on heart and circulation problems

Blood pressure and heart rate that were increased due to smoking come down and the risks of heart disease and stroke drop.

The increased risk of coronary heart disease is reduced by 50 percent in those who have quit (as compared to continuing smokers) one year after cessation, but the risk level doesn’t compare to that of nonsmokers until 15 years after quitting.

Circulatory impairment to the heart, brain, and legs caused by smoking is irreversible. The toxins in cigarette smoke damage the inner lining of the blood vessels, which does not resolve after giving up smoking.

Cancer risk

More than 50 percent of lung cancers are now being diagnosed in ex-smokers. The risk of lung cancer in a smoker will match that of nonsmokers about 10 to 15 years after smoking cessation.

Smoking cessation reduces by half the risk for cancers of the oral cavity and the esophagus during the first five years after quitting, but ex-smokers will always continue to have an increased risk as compared to the risk in those who have never smoked.

Smoking is the strongest risk factor for developing urinary bladder cancer. It is also known to be dominant in causing kidney cancer. Quitting reduces this risk by half after a few years of smoking, but the risk does remain elevated for decades.

Similarly, the risk of pancreatic cancer and colon cancer. After giving up smoking, the risk somewhat reduces about 10 years after quitting but still stays somewhat elevated.


Smoking causes premature facial wrinkling through vasoconstriction of the facial capillaries. The effect of this reduced blood flow is visible as emerging wrinkles at the corner of the eyes and pale, grayish wrinkled skin on the cheeks. These wrinkles emerge as few as five years after beginning to smoke and are largely irreversible.


Infertility is common among smokers. However, it is totally reversible when you give up smoking during your reproductive years.


Bone mineral loss (osteoporosis), hip fractures, and spinal arthritis are other health complications of long-term smoking, which are irreversible even after quitting.

But the fact remains:

Various people react to smoking in different ways. An elderly person may still be smoking at the age of 80 and above and feel fine. And, you may have a smoker of age 40 years or less struggling with emphysema and bronchial asthma. This all points to genetics, which we still have to fathom.