Chronic bronchitis (CB) is a case of upper respiratory inflammation that is almost exclusively caused by smoking (1). In fact, non-smokers don't get CB even after long-term inhalation of industrial pollutants, but those pollutants might just exacerbate existing CB in smokers (1).
You'd think at first that this was just a lung disease. But when you've had CB for awhile, poor breathing can produce hypoxemia and hypercapnia, which can trigger a pulmonary vasoconstriction reflex that increases the right heart's workload (1).
And chronic hypoxemia can do further damage. It will also increase secresion from the kidneys of erythropoietin (1). This, causes the bone marrow to increase red blood cells (which is why you can test for CB using a hematocrit assay) (1). The high red blood cell count make your blood flow like maple syrup, which can cause possible thrombosis (1).
1. Nowak TJ, Handford AG. Pathophysiology: Concepts and Applications for Health Professionals. New York: McGraw-Hill, 2004, p318.