Chronic bronchitis is the most common disease of the bronchopulmonary system, and at the same time the least studied, which is to some extent due to the presence of many factors predisposing to this ailment.
In the mechanism of development of bronchitis, many scientists assign a leading role to the infectious principle, since often chronic bronchitis is a consequence of untreated acute. However, most pulmonologists around the world consider smoking to be the main cause of the development of chronic bronchitis. It was 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 you know, oxygen enters the lungs through the bronchi, and carbon dioxide is removed from the lungs. The bronchi perform a protective function. The cells of their epithelium are equipped with cilia (which is why it is called the ciliated epithelium), which, like an escalator, carry up the mucus accumulated in the bronchi, dust particles and microorganisms that have been inhaled by the air.
Whatever the root cause of the inflammatory process that developed in the mucous membrane of the bronchi, it leads to a restructuring of the structure and function of the bronchial epithelium, to a violation of the secretion of mucus. As a result, more mucus is secreted, it becomes too viscous, ciliated epithelial cells begin to lose cilia, the epithelium “balds”, and the excess of viscous mucus makes the movement of the remaining cilia more difficult, the escalator function of the epithelium is impaired. Mucus, accumulating in the lumens of the bronchi, irritates the so-called cough receptors located in their walls, coughing occurs – the first signal of distress in the airways.
True, 5-10% of patients with bronchitis do not have a cough. This happens when the process affects the small and smallest bronchi and bronchioles, in which cough receptors are absent.
If the patient is often disturbed by a cough, but he does not pay attention to it, does not go to the doctor, does not actively treat acute bronchitis, does not quit smoking, then pathogenic microorganisms caught in mucus with inhaled air begin to multiply intensively. The phenomenon of the thermostat arises in the bronchi: favorable conditions are created for the vital activity of pathogenic microorganisms. The mucus becomes purulent and clears its throat in the form of purulent sputum of yellow-green color, sometimes with an unpleasant odor, which indicates the development of mucopurulent bronchitis. In this case, the inflammation passes to the deeper layers of the walls of the bronchi. The well-being of patients usually worsens, body temperature may increase, weakness, sweating, and working capacity decrease.
Violations of the body’s immune system caused by viral and bacterial infections (flu, tonsillitis), vitamin deficiency, and starvation, to which some carelessly resort to lose extra pounds, play a significant role in the development of mucopurulent bronchitis. All this negatively affects the mechanisms of local protection of bronchial tissues from pathogenic microbes. For example, the content of lysozyme in the epithelial cells, a substance with a bactericidal effect, is reduced. Pathogenic microbes become more active, the body’s sensitivity to them increases, which determines the further progression of the inflammatory process in the bronchi.
Risk factors such as overweight and lack of exercise are also directly related to the development of chronic bronchitis. Obese, low-moving people have a high standing diaphragm, which complicates pulmonary ventilation, normal air movement through the broncho-pulmonary system, the depth of breathing decreases, and it is more difficult for the bronchi to get rid of sputum.
Blockage of the bronchi with viscous mucus leads to the fact that the intake of inhaled oxygen into the lungs is difficult, oxygen starvation develops. And even a small physical activity causes shortness of breath in the patient.
Over time, patency of the bronchi is impaired, especially on exhalation. Due to the fact that it is difficult to exhale, the alveoli swell, the partitions between them collapse, and emphysema develops. Since emphysema disrupts blood circulation in the pulmonary capillaries, the right ventricle of the heart has to work harder to push blood through them. The right atrium and ventricle hypertrophy, and then severe heart failure develops, manifested by shortness of breath, tachycardia (palpitations), cyanosis (cyanosis of the skin), swelling, enlarged liver, swelling and pulsation of the cervical veins, impaired function of many organs and systems. The treatment of such patients becomes difficult.
And the fact that chronic bronchitis sometimes leads to a tragic end, most often the patients themselves are guilty, irresponsibly referring to their health.