What is chronic bronchitis?

Causes

With chronic bronchitis, the airways in the lungs experience inflammation. When these airways become irritated, thick mucus forms inside the airways, making it difficult to breathe.

The most common causes of chronic bronchitis include cigarette smoking and exposure to secondhand cigarette smoke. Air pollution, infections, and allergens worsen the symptoms of bronchitis.

Risk Factors

Cigarette smoking is the single greatest risk factor for developing chronic bronchitis. More than 90 percent of chronic bronchitis patients are or have been smokers, and about 15 percent of all smokers develop the disease. The more a person smokes and the longer he or she smokes, the greater the risk is of developing chronic bronchitis. Frequent and long-term smoking also increases the risk that the chronic bronchitis will be severe.

Other factors that may increase the chance of developing chronic bronchitis include long-term exposure to chemicals, dust, and other substances that have been inhaled; long-term cigar or marijuana smoking; uncontrolled asthma; and long-term exposure to air pollution.

Symptoms

Symptoms of chronic bronchitis include coughing up mucus, coughing up mucus streaked with blood, and shortness of breath (difficulty breathing). Difficulty breathing may especially occur after mild activity or exercise. Other symptoms include recurring respiratory infections that cause symptoms to worsen; wheezing when breathing; fatigue; swelling of the ankles, feet, and legs; and headaches.

Screening and Diagnosis

To diagnose chronic bronchitis, symptoms of productive cough must have been present for three or more months in at least two consecutive years, and not have been caused by another condition. A doctor will ask about symptoms and medical history and perform a physical examination.

Tests may include breathing tests to check lung function, arterial blood gas tests, chest X-ray (a test that uses radiation to take a picture of structures inside the chest), blood tests to determine complete blood count and oxygen saturation of the blood, exercise stress testing to test lung function, and a CT scan of the chest (a type of X-ray that captures 3-D images of the internal organs).

Treatment and Therapy

There is no cure for chronic bronchitis, but there are treatments that can reduce symptoms and improve lung function. The best way to reduce symptoms is to stop smoking. Short-acting bronchodilator medications may be prescribed to help open the airways in the lungs and improve breathing. Long-acting bronchodilator medication may be prescribed as well, and steroids may be prescribed to help improve breathing. Antibiotics are rarely prescribed to treat bronchitis. However, they may be needed to treat a lung infection that often accompanies the illness. A small percentage of patients may need chronic antibiotic therapy.

Oxygen therapy can restore oxygen to parts of the body depleted because of chronic bronchitis. Exercise can also help. Breathing exercises can help to improve lung function, and are usually done under the supervision of a respiratory therapist. A regular exercise program can reduce symptoms and improve lung function.

Prevention

The best way to prevent chronic bronchitis is to stop smoking, or avoiding smoking altogether for nonsmokers. Inhalation of other triggers such as air pollution, chemicals, and dust should also be avoided as much as possible. Early diagnosis and treatment of the condition will preserve lung function and reduce symptoms.

Bibliography

"Chronic Bronchitis." MedlinePlus. US National Library of Medicine, 12 Aug. 2015. Web. 28 Oct. 2015.

"Chronic Obstructive Pulmonary Disease (COPD) Includes: Chronic Bronchitis and Emphysema." CDC. US Dept. of Health and Human Services, 29 Apr. 2015. Web. 28 Oct. 2015.

Halbert, R. J., et al. “Global Burden of COPD: Systematic Review and Meta-Analysis.” European Respiratory Journal 28.3 (2006): 523–532. Print.

Lopez, A.D., et al. “Chronic Obstructive Pulmonary Disease: Current Burden and Future Projections.” European Respiratory Journal 27.2 (2006): 397–412. Print.

Mayo Clinic Staff. “Bronchitis.” Mayo Clinic. Mayo Foundation for Medical Education and Research. 1 Apr. 2014. Web. 28 Oct. 2015.