Fig 1. Acute bronchitis. The lumen of the normal airway becomes narrowed and large amounts of mucus are secreted.
Fig 2. Chronic bronchitis. A comparison of healthy and inflamed bronchi.
Bronchitis is inflammation of the bronchi. Acute bronchitis, often due to virus infection, is accompanied by cough and fever and is short-lived. Antibiotics are needed only if there is bacterial infection.
Chronic bronchitis is a more serious, often disabling and finally fatal disease. The main cause is smoking which irritates the lungs and causes overproduction of mucus. The cilia fail, and sputum has to be coughed up. Bronchi thus become liable to recurrent bacterial infection, sometimes progressing to pneumonia. Areas of lung become non-functional, and ultimately cyanosis and heart failure may result.
Treatment includes physiotherapy, antibiotics, and bronchial dilator drugs. Stopping smoking limits damage and may improve early cases.