What is Pneumonia?

Pneumonia is an infection of the lungs caused by bacteria, viruses, fungi or parasites. Pneumonia can affect people of any age. However, the elderly (> 65 years old) and young children are most vulnerable. Pneumonia obstructs the normal exchange of air inside the lungs, which leads to low levels of oxygen in the blood and impaired removal of carbon dioxide from the body. The severity of pneumonia ranges from mild to life-threatening. In Hong Kong, pulmonary tuberculosis is still commonly seen, which needs to be considered in case of pneumonia not responding to usual antibiotics.

Pneumonia can affect people of any age, and can be triggered by cold or flu bouts.

  • People who have a weak immune system due to diseases (e.g. diabetes, cancer) or medications (e.g. steroid, anti-rejection drugs) are at high risk of developing pneumonia.
  • Young children are considered most susceptible, as well as the elderly, who may suffer from chronic illnesses such as COPD, diabetes and congestive heart failure.
  • Viral pneumonia often affects people living in areas with epidemics of respiratory viral infections (e.g. MERS, influenza) or those who recently travelled to these places.
  • Contact with people having highly infectious conditions, e.g. tuberculosis.
  • Various micro-organisms including bacteria, viruses, fungi and parasites. Sometimes tuberculosis can present as pneumonia.

Symptoms associated with pneumonia differ considerably depending on the cause and  health condition of patients. These may include:

  • Blue tinge to skin, lips, tongue and fingertips due to lack of oxygen
  • Breathing difficulty and wheezing
  • Chest pain when breathing and coughing
  • Coughing
  • Green or yellow-coloured sputum
  • Fever and chills

Treatment depends on the causative agent that triggers the infection and the severity of illness, which may include:

  • Antibiotics to treat bacterial pneumonia
  • Antiviral medication to treat viral pneumonia
  • Hospitalisation may be required for severe cases of pneumonia for intravenous antibiotics, oxygen therapy, and close monitoring
  • Medication to alleviate symptoms including cough, fever, chest pains and muscle aches (given together with suggested antibiotics and antiviral medication)
  • Plenty of bed rest, a healthy diet and lots of fluid are encouraged
  • If confirmed tuberculosis, a combination of anti-tuberculosis drugs will need to be taken for six to nine months. The most common drugs include:
    • Isoniazid
    • Rifampcin
    • Pyrazinamide
    • Ethambutol
    • Streptomycin

  • Acute respiratory distress syndrome if pneumonia affects both lungs, leading to gas exchange failure
  • Bacteraemia, with bacteria entering blood
  • Bronchiectasis, due to destruction of airways
  • Lung abscess
  • Pleural effusion, a kind of fluid accumulation between chest wall and the lung
  • Septic shock can trigger circulation failure and lead to kidney failure and blood clotting abnormalities

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