Smoking causes chronic obstructive pulmonary disease, or COPD, which includes emphysema, or enlargement of the air sacs, or alveoli; chronic bronchitis, or chronic cough-producing phlegm; and small airways disease, or narrowing of bronchioles, according to "Harrison's Principles of Internal Medicine". COPD partly reverses after smoking cessation, but the earlier a person stops smoking, the more beneficial an effect.
Cilia Recovery
Cilia, the tiny hairs lining the respiratory tract that sweep out inhaled particles, serve as the first line of defense against pneumonia. Cigarette smoking adversely affects cilia in two ways: Smoking has cilia-depressant activity, and according to the "American Journal of Respiratory Critical Care Medicine," it reduced exhaled nitric oxide in healthy volunteers. according to a study conducted by Dr. S.A. Kharitonov and colleagues. Nitric oxide helps in the movement of cilia. After quitting smoking, cilia begin working again. It takes several months until the cilia fully recover, according to MayoClinic.com.
Decrease in Phlegm
Smoking causes chronic bronchitis, or inflammation of the airways, which stimulates production of mucus, or phlegm; this damage causes further obstruction of the airways. Chronic phlegm means coughing up phlegm in the morning and/or at any time during the day or night for up to three months each year. According to "Mediators of Inflammation," as stated by Dr. Izolde Bouloukaki, a study of induced sputum from 68 healthy smokers before and after six months and one year of smoking cessation and from 10 healthy never-smokers showed smoking cessation can equilibrate certain inflammatory cells of smokers with those of nonsmokers within six months.
Airflow Improvement
An important clinical measurement of airflow in a smoker uses the volume of air exhaled in the first second of maximal expiratory effort, or FEV1. The normal FEV1 should be 75 percent of predicted. Obstructive pulmonary diseases like COPD cause a decline in FEV1 related to number of packs of cigarettes smoked and number of years, or pack-years. According to the "American Journal of Respiratory Critical Care Medicine," a study of 3,926 smokers with mild-to-moderate airway obstruction showed that participants who stopped smoking experienced an improvement in FEV1 of 47 mL, or 2 percent, in the year after quitting on average. This indicates a modest improvement in lung function.
References
- "Harrison's Principles of Internal Medicine"; Dennis Kasper, M.D.; 2005
- "American Journal of Respiratory Critical Care Medicine"; Smoking Cessation and Lung Function in Mild-to-Moderate Chronic Obstructive Pulmonary Disease; Paul D. Scanlon et al.; 2000
- Mayo Clinic: Quit Smoking
- "American Journal of Respiratory Critical Care Medicine"; Acute and Chronic Effects of Cigarette Smoking on Exhaled Nitric Oxide; Dr. S.A. Kharitonov et al.; 1995
- "Mediators of Inflammation"; Maintained Smoking Cessation for 6 Months Equilibrates the Percentage of Sputum CD8+ Lymphocyte Cells With That of Nonsmokers; Dr. Izolde Bouloukaki; 2009
