Written by Pharmacist, Kuan Xin Jing

What is Pneumonia?

Pneumonia is an infection that inflames the air sacs in one or both lungs. The air sacs may fill with fluid or pus (purulent material), causing cough with phlegm or pus, fever, chills, and difficulty breathing. A variety of organisms, including bacteria, viruses and fungi, can cause pneumonia.

Signs and Symptoms


See your doctor promptly if you have the following signs and symptoms:

  • Have a high fever
  • Have shaking chills
  • Have a cough with phlegm (a slimy substance), which doesn’t improve or worsens
  • Develop shortness of breath with normal daily activities
  • Have chest pain when you breathe or cough
  • Feel suddenly worse after a cold or the flu

Risk factors


Anyone can get pneumonia, but young children and people over the age of 65 have a higher risk of developing the condition. Some other factors that can increase your risk of getting pneumonia include:

  • Having a weak immune system, which can occur in people who have HIV/AIDS;
  • Taking anti-inflammatory medications, such as corticosteroids;
  • Other lung conditions, such as asthma, chronic obstructive pulmonary disease (COPD) or bronchiectasis, and;
  • Smoking, which can damage your lungs and make it harder for your immune system to prevent lung infections.

Classification of pneumonia

Classification by where it was acquired

Type of pneumonia Description
Community-acquired pneumonia (CAP)

·         Occur before or within 48 hours of hospital admission in patients who have not been hospitalized for > 14 days

·          Most frequently Streptococcus pneumoniae (20-75%)

Mycoplasma pneumoniae

Chlamydia pneumoniae

Legionella spp.

Atypical bacterial pathogens (2-25%)

Viral infections (8-12%)

Hospital acquired pneumonia

·         Pneumonia developing > 2 days after hospital admission

·         Likely aerobic gram-negative bacilli, e.g. Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, Acinetobacter species (~65%)

·         Staphylococcus aureus (~15%)

·         In ICU, > 50% S. aureus infections are methicillin-resistant (MRSA)

·         S. aureus more common in diabetics and ICU patients

Diagnosis Method

  • Blood tests – To confirm an infection and identify the type of organism causing the infection
  • Chest X-ray – Determine the extent and location of the infection
  • Pulse oximetry – Determine the oxygen level in your blood
  • Sputum test – A sample of fluid from your lungs (sputum) is taken after a deep cough 

If you’re older than age 65, are in the hospital, or have serious symptoms or health conditions. Additional tests may include:

  • CT scan
  • Pleural fluid culture


Specific treatments depend on the type and severity of your pneumonia, your age and your overall health. The options include:

  • Antibiotics. May take time to identify the type of bacteria causing your pneumonia and to choose the best antibiotic to treat it. 
  • Cough medicine. May be used to calm cough so that you can rest. However, coughing helps loosen and move fluid from your lungs. Hence, it’s not a good idea to eliminate your cough completely. 
  • Fever reducers/pain relievers. May be taken as needed for fever and discomfort. 



  • Vaccination
  • Wash your hands with soap and water or alcohol-based rubs to kill germs.
  • Don’t smoke. Smoking damages your lungs’ ability to filter out and defend against germs. 
  • Keep your immune system strong. 


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