Bronchitis occurs when there is swelling of the lining of the large airways called bronchi within the lungs. This swelling due to inflammation, irritation and infection leads to more mucus formation than normal. This blocks the airflow through the lungs and may damage the lung eventually. There are two basic types of bronchitis:-

• Acute bronchitis – this lasts for 2 to 4 weeks and is usually responsive to therapy
• Chronic bronchitis – this is a different entity and leads to long term damage to the inner walls of the airways in the lungs. This is part of a group of lung diseases called chronic obstructive pulmonary disease or COPD. This is a progressively worsening condition that cannot be cured.

Pneumonia

Around one person in 20 with bronchitis may develop a secondary infection in the lungs leading to pneumonia. The infection is commonly bacterial although the initial infection that caused the bronchitis may be viral.

Specifically, the infection affects the tiny air sacs known as alveoli. Those at risk of pneumonia include:-

• Extremes of ages including infants and babies and elderly with a diminished immunity that makes them susceptible to a secondary infection.
• Smokers have a diminished immunity and also are prone to repeated chest infections. They are prone to develop secondary bacterial pneumonia after a bout of bronchitis.
• Patients with heart or lung diseases co-existing with bronchitis are also at risk of pneumonia. This includes heart failure patients, asthma patients, COPD patients.
• Those with a weakened immunity are also at risk of developing complications of bronchitis like pneumonia.

Pneumonia symptoms include:-

• high fever
• difficulty in breathing or breathlessness even when resting
• rapid heart rate
• rapid breathing rate and shallow breathing
• sweating and shivering along with fever
• loss of appetite
• chest pain
• cough
• loss of appetite and refusal to feed in infants
• general feeling of unwell and listlessness in the affected infant

Pneumonia is unlikely if all of the following findings are not present:-

• fever over 38 degree C
• rapid breathing rate over 24 per minute
• rapid heart rate of over 100 per minute
• on hearing with stethoscope typical breath sounds including rales and fremitus.

Mild pneumonia is treatable at home with antibiotics and plenty of fluids and bed rest. More severe cases may necessitate hospital admission.

Ventilator assistance may be needed if the patient goes into respiratory failure and is unable to breathe on his or her own. Usually these patients would need intravenously administered antibiotics.

Development of COPD

Chronic bronchitis has the propensity to lead to long term COPD with progressively diminishing lung reserves and breathing difficulties. COPD further raises the risk of occasional flare ups and increased risk of recurrent and frequent chest infections.