The cause of chronic bronchitis

The cause of chronic bronchitis
Chronic bronchitis (chronic bronchitis, chronic bronchitis short) refers to the trachea, bronchial mucous membrane and its surrounding tissue of chronic non-specific inflammation. Clinical to cough, sputum or breathing with the onset of chronic and repeated the process is characterized. If the slow progress of illness, often with obstructive pulmonary emphysema, and even pulmonary hypertension, pulmonary heart disease. It is a seriously endanger the health of the people of the common diseases, particularly the elderly多见.

Cause not yet entirely clear, will generally be divided into external factors and internal factors cause the two aspects.
First, external factors

(A) smoking at home and abroad, and studies have proved that smoking is closely related to the occurrence of chronic bronchitis. The longer smoke, smoke in the greater prevalence rate is also higher. After quitting smoking can reduce the symptoms or disappeared, conditions eased, even cured. Animal experiments show that after the absorption of smoke sympathetic excitatory increased, bronchial spasm contraction; airway epithelial cells by inhibiting clearance; bronchial goblet cell proliferation, increased mucus secretion, so that the airway purification capacity decreased bronchial mucosal congestion, edema , Mucus build-up, swallowed up in the alveolar cells weakened, are easily infected from. - Smokers from squamous cell metaplasia, mucosal gland hyperplasia, mast and bronchial spasms, easy to infection and disease.

(B) factors of chronic bronchitis infection is an important factor in the development, mainly for the virus and bacterial infections, nasal virus, mucus virus, adenovirus and respiratory syncytial virus as多见. The virus and mycoplasma infection with the virus airway mucosal injury on the basis of secondary bacterial infections can be. The results showed that from the sputum culture, Haemophilus influenzae, Streptococcus pneumoniae, and Streptococcus A Neisseria maximum of four to see. Although infection with the closely related to the development of chronic bronchitis, but there is no sufficient evidence that its first cause. That is the only secondary infections and chronic bronchitis aggravated an important factor in the development of lesions.

(C) physical and chemical factors, such as the irritating smoke, dust, air pollution (such as sulphur dioxide, nitrogen dioxide, chlorine, ozone, etc.) to stimulate the chronic, often induced by the cause of chronic bronchitis. Contact irritating dust and harmful industrial gases workers, chronic bronchitis prevalence rate than those not exposed to high. Air pollution is also important induced cause of the disease.

(D) the cold weather often causes chronic bronchitis and attack the important incentives. Increase the incidence of acute chronic bronchitis and common cold season in the quarter, especially sudden changes in climate. Cold air stimulate the respiratory tract, in addition to weakening the mucous membrane of respiratory defense functions, but also reflection caused by bronchial smooth muscle contraction, blood circulation mucosal secretions from the obstacles and difficulties, is conducive to secondary infection.

(5) allergic factors According to the survey, asthmatic bronchitis are often allergic history. In patients with sputum eosinophils in the quantity and histamine levels have increased tendency that some patients with allergy-related factors. Dust, dust mites, bacteria, fungi, parasites, pollen and chemical gas, can become allergic pathogenic factors.

Second, due to

(A) Local defense respiratory reduce the normal immune function and respiratory function with sound defense, with the inhalation of air filtration, heating and humid role in the trachea, bronchial mucous membrane of mucus clearance and cough reflex, to purify or exclude foreign body And excessive secretions; small bronchial and alveolar still exist in the secretory immunoglobulin A (SIgA), have anti-viral and bacterial effect. Therefore, under normal circumstances, lower respiratory tract always maintain sterile state. Systemic or respiratory partial defense and weakened immune function, the incidence of chronic bronchitis to provide the internal conditions. The elderly due to respiratory immune dysfunction, immunoglobulin reduced respiratory function defense degradation, single-core - phagocytes system functions, such as recession, induced by the higher prevalence rate.

(B) autonomic dysfunction when the sympathetic response to increased respiratory deputy, the normal person does not work to stimulate the weak, can cause bronchial spasms contraction, the increase in secretions, and have a cough, sputum, wheezing and other symptoms.

The above factors, when the body resistance weakened, there are different degrees of airway sensitivity (susceptibility) on the basis of a variety of external factors or the existence of long-term repeatedly, can develop into chronic bronchitis. Smoking damages such as long-term respiratory mucosa, coupled with the repeated microbial infections, chronic bronchitis, or even develop into chronic obstructive pulmonary emphysema or chronic pulmonary heart disease.