Chronic bronchitis is the most common disease of the broncho-pulmonary system, and at the same time the least studied, which is to a certain extent due to the presence of many factors predisposing to this ailment.
In the mechanism of development of bronchitis, many scientists assign the leading role to the infectious disease, as often chronic bronchitis is a consequence of undertreated acute. However, most pulmonologists all over the world consider smoking to be the main cause of chronic bronchitis. It is established that inhalation of tobacco smoke causes an inflammatory process in the mucous membrane lining the bronchi from the inside, which leads to a violation of their structure and function.
As is well known, oxygen passes through the bronchi to the lungs, and carbon dioxide is removed from the lungs. The bronchi also perform a protective function. The cells of their epithelium are equipped with cilia (which is why it is called ciliated epithelium), which, like an escalator, carry up the mucus accumulated in the bronchi, the dust particles that have been inhaled with inhaled air, and microorganisms.
Whatever the underlying cause of the inflammatory process that has developed in the bronchial mucosa, it leads to a restructuring of the epithelium of the bronchi, to a violation of the secretion of mucus. As a result, more mucus is secreted, it becomes too viscous, the cells of the ciliary epithelium begin to lose cilia, the epithelium becomes bald, and an excess of viscous mucus makes it more difficult for the remaining cilia to move, the escalator function of the epithelium is disturbed. Mucus, accumulating in the lumen of the bronchi, irritates the so-called cough receptors located in their walls, coughing occurs – the first signal of trouble in the respiratory tract.
True, 5-10% of patients with bronchitis have no cough. This happens when the process affects the smallest and smallest bronchi and bronchioles, in which the cough receptors are absent.
If the patient has become frequently bothered by a cough, but he does not pay attention to it, does not go to the doctor, does not actively heal acute bronchitis, does not stop smoking, then pathogenic microorganisms that have fallen into the mucus with inhaled air begin to multiply. In the bronchi, a thermostat phenomenon occurs: favorable conditions are created for the vital activity of pathogens. The mucus becomes purulent and coughs in the form of a purulent sputum of yellow-green color, sometimes with an unpleasant odor, which indicates the development of mucopurulent bronchitis. At the same time, inflammation passes to the deeper layers of the bronchial walls. The state of health of patients usually worsens, the temperature of the body may rise, weakness, sweating appear, and efficiency decreases.
In the development of mucopurulent bronchitis a significant role is played by impaired immune systems of the body caused by postponed viral and bacterial infections (flu, sore throat), vitamin deficiency, starvation, which some carelessly resort to in order to lose those extra pounds. All this adversely affects the mechanisms of local protection of bronchial tissues against pathogenic microbes. For example, the content in the epithelial cells of lysozyme, a substance with a bactericidal effect, decreases. Pathogenic microbes become more active, the sensitivity to them of the body increases, which leads to the further progression of the inflammatory process in the bronchi.
Risk factors such as overweight and hypodynamia are also directly related to the development of chronic bronchitis. In obese, little moving people, a high standing of the diaphragm is noted, which complicates pulmonary ventilation, normal air flow through the broncho-pulmonary system, decreases the depth of breathing, and makes it more difficult for the bronchi to get rid of sputum.
The occlusion of the bronchi with viscous mucus leads to the fact that the intake of inhaled oxygen into the lungs becomes difficult, and oxygen starvation develops. And even a small physical exertion causes shortness of breath in a patient.
Over time, the patency of the bronchi is disturbed, especially on the exhalation. Due to the fact that exhalation is difficult, the alveoli swell, the walls between them are destroyed, emphysema develops. Since emphysema impairs blood circulation in the pulmonary capillaries, the right ventricle of the heart has to work with a greater load in order to push blood through them. The right atrium and ventricle hypertrophy, and then develop severe heart failure, manifested by shortness of breath, tachycardia (rapid heartbeat), cyanosis (cyanosis of the skin), edema, liver enlargement, swelling and pulsation of the neck veins, dysfunction of many organs and systems. Treatment of such patients becomes difficult.
And the fact that chronic bronchitis sometimes leads to a tragic end is most often caused by the patients themselves, who are irresponsible about their health.