An immunologically mediated inflammatory disease of the airways, asthma is typically distinguished from chronic obstructive pulmonary disease by the reversibility of airway obstruction. Persons with emphysemic COPD have reduced single breath diffusing capacity for carbon monoxide while persons with chronic bronchitic COPD have near normal single breath diffusing capacity for carbon monoxide. A smoker directly inhales mainstream smoke through a burning cigarette. Adverse Health Effects Cigarette smoke causes air passages to close up, making breathing more difficult. Inhalation of cigarette smoke decreases the lungs' ability to defend against infection because irritating gases and particles from cigarette smoke slow down the cilia, one of the lungs' clearance mechanisms.
Cigarette smoke causes chronic inflammation in the lungs, leading to chronic bronchitis.
It also leads to the destruction of lung tissue that occurs in emphysema by changing the enzyme balance of the lungs. Moreover, smoking is a significant cause of cardiovascular disease. Nicotine, the addictive component of tobacco, increases heart rate and blood pressure. Smokers experience a threefold to fourfold increase in risk for myocardial infarction, cardiac arrest, and stroke. Mechanism Tobacco use exposes smokers to polycyclic aromatic hydrocarbons and heterocyclic amines, compounds that can interfere with the process of cellular replication.