The lungs contain a branching system of airways leading to the air sacs, where gas exchange occurs. Each branch division gives rise to narrower airways, akin to branching tree limbs. The bronchi are the larger airways of the lungs. Infections, chronic inflammation, environmental inhalants, allergic disorders and inherited conditions can cause bronchial lung diseases, which may significantly interfere with overall lung function.
Asthma
Asthma is a chronic condition in which the bronchi exhibit periodic constriction, provoking shortness of breath, coughing, chest tightness and wheezing. Various environmental and emotional conditions can trigger an asthma attack. In some cases, the provoking factor remains unknown. The American Academy of Allergy, Asthma and Immunology explains that the airways of asthmatics are abnormally inflamed, which contributes to their reactivity. Increased mucus production and airway swelling further exacerbate asthma symptoms. Asthma treatment typically involves anti-inflammatory medications to control airway swelling, inflammation and reactivity. "Rescue" medications control acute symptoms during an asthma attack.
Acute Bronchitis
Acute bronchitis describes a short-term inflammation of the bronchial airways. Inflammation triggers increased mucus production, leading to a cough. Other symptoms of acute bronchitis include low-grade fever, chest soreness, fatigue, sore throat and mild head or body aches. The Centers for Disease Control and Prevention reports that viruses most commonly cause acute bronchitis including various strains of coronavirus, rhinovirus, adenovirus, parainfluenza and influenza, enterovirus and respiratory syncytial virus. Most symptoms of acute bronchitis clear within approximately two weeks. Cough, however, often clears more slowly. Given that most cases of acute bronchitis are viral, antibiotics typically do not affect the course of the illness.
Chronic Obstructive Bronchitis
Chronic obstructive bronchitis is one form of chronic obstructive pulmonary disease, or COPD. The Merck Manual for Healthcare Professionals explains that the disease process involves chronic inflammation of the bronchial airways with tissue swelling and significantly increased mucus production. These factors reduce the open space in the airways, causing obstruction and decreased airflow through the lungs. Chronic cough with mucus production is the hallmark symptom of chronic obstructive bronchitis. The National Heart, Lung and Blood Institute relates that cigarette smoking is the leading cause of chronic obstructive pulmonary disease. Less common causes include chronic exposure to chemicals, pollutants and environmental or industrial dust.
Bronchiectasis
Bronchiectasis is a condition characterized by progressive destruction of the large bronchi due to chronic inflammation and serial infections. The National Heart, Lung and Blood Institute relates that long-standing inflammation damages the lining of the bronchi, resulting in an inability to clear mucus from the airways. Over time, the airways dilate and fill with mucus plugs. Scarring causes distortion of the airways and surrounding lung tissue. According to The Merck Manual for Healthcare Professionals, most cases of bronchiectasis are due to cystic fibrosis. Other causes include common variable immunodeficiency, primary ciliary dyskinesia, Sjögren's syndrome and bronchopulmonary aspergillosis.
References
- National Heart, Lung and Blood Institute: Asthma
- American Academy of Allergy, Asthma & Immunology: Asthma
- "American Family Physician"; Diagnosis and Management of Acute Bronchitis; Doug Knutson, M.D., Chad Braun, M.D.; May 2002
- Centers for Disease Control and Prevention: Bronchitis (Chest Cold)
- National Heart, Lung and Blood Institute: COPD
