Overview
Pneumonia is an infection of the lungs. Unlike diseases with one specific cause, pneumonia can be triggered by many different germs, bacteria, viruses, fungi, and occasionally parasites, and the right treatment depends heavily on which type is involved.
Key Fact
Warning
AT A GLANCE
Disease Summary
Symptoms
Common Symptoms
Most people with pneumonia experience one or more of the following symptoms.
Cough
Fever
Difficulty Breathing
Chest Pain
Fatigue
Danger Signs
Seek urgent medical attention immediately if any of the following symptoms develop.
Severe Difficulty Breathing
Confusion
Bluish Lips or Face
Rapid Heartbeat or Low Blood Pressure
Diagnosis
Clinical Assessment
Chest X-ray
Identifying the Cause
Laboratory Tests
Chest X-ray
Confirms the presence, location, and extent of lung infection.
Complete Blood Count (CBC)
Helps identify signs of infection and assess its severity.
Sputum Culture
Can identify the specific bacteria causing pneumonia, when bacterial infection is suspected.
Pulse Oximetry
Measures blood oxygen levels and helps determine how severely the infection is affecting breathing.
Laboratory Note
Identifying the exact cause is not always possible, and treatment often begins based on clinical judgement before all results are available.
Treatment
Antibiotics
Used for bacterial pneumonia. Antibiotics have no effect on viral pneumonia, making accurate diagnosis important.
Supportive Care
Fluids, rest, and fever management support recovery for both bacterial and viral pneumonia. Oxygen therapy may be needed in more severe cases.
Treatment Note
Completing a full antibiotic course, even after feeling better, is important for bacterial pneumonia. Viral pneumonia usually improves with supportive care alone.
Prevention
Get recommended vaccines
Vaccines against some of the bacteria and viruses that cause pneumonia, including pneumococcal and influenza vaccines, significantly reduce risk.
Practise good hand hygiene
Regular handwashing reduces the spread of many germs that can lead to pneumonia.
Avoid smoking
Smoking damages the lungs’ natural defences and significantly increases the risk of pneumonia.
Manage chronic health conditions
Conditions such as diabetes or heart disease increase the risk of pneumonia and its complications, so ongoing management matters.
Prevention Note
Young children, older adults, and people with weakened immune systems benefit most from preventive vaccines and should discuss recommended vaccinations with a healthcare provider.
Risk Factors
High Risk
These individuals are more likely to develop severe pneumonia.
- Adults over 65
- Infants and young children
- People with weakened immune systems
Increased Risk
These groups have a higher chance of developing pneumonia.
- People with chronic lung or heart conditions
- People who smoke
- People recently hospitalised or on a ventilator
Exposure Factors
Situations that increase the risk of developing pneumonia.
- Recent viral respiratory infection
- Exposure to air pollution or occupational irritants
- Limited access to vaccination
Risk Note
Pneumonia risk rises significantly after another respiratory infection, such as influenza, which can weaken the lungs’ natural defences.
Complications
Pleural Effusion
Fluid can build up around the lungs, sometimes requiring drainage.
Bacteremia
The infection can spread into the bloodstream, becoming a more widespread and serious illness.
Respiratory Failure
Severe pneumonia can prevent the lungs from supplying enough oxygen to the body, requiring intensive care.
Complication Note
Most people recover fully from pneumonia with appropriate treatment. Complications are more likely in older adults, young children, and people with weakened immune systems.
When to Seek Medical Care
Severe Difficulty Breathing
Rapid, laboured, or painful breathing requires immediate medical care.
Confusion
New confusion, particularly in older adults, is a medical emergency.
Bluish Lips or Face
Indicates low blood oxygen and requires emergency care.
High Fever Not Improving
A fever that persists or worsens despite treatment should be reassessed by a healthcare provider.
Emergency Advice
Older adults and young children can deteriorate quickly with pneumonia. Do not wait to see if symptoms improve on their own.
Prognosis
Good with Appropriate Treatment
Most people recover fully from pneumonia within one to three weeks with appropriate treatment.
More Serious in Certain Groups
Older adults, young children, and people with weakened immune systems face a higher risk of severe illness and complications.
Recovery Time Varies by Cause
Bacterial pneumonia often improves within days of starting antibiotics, while viral pneumonia may take longer to resolve.
Prognosis Note
Pneumonia remains a leading cause of hospitalisation and death from infection worldwide, particularly among young children and older adults. Prompt diagnosis and treatment significantly improve outcomes.
Differential Diagnosis
Tuberculosis
Tuberculosis shares several respiratory symptoms with pneumonia, including cough, fever, and chest findings, but typically develops more gradually.
Sepsis
Severe pneumonia can itself trigger sepsis, and the two conditions can be difficult to distinguish in advanced cases.
Bronchitis
Bronchitis causes cough and chest discomfort but does not typically show the lung infiltrates seen on a chest X-ray in pneumonia.
Clinical Note
Because several respiratory conditions share similar symptoms, a chest X-ray and clinical assessment together are important for accurate diagnosis.
References
World Health Organization (WHO)
World Health Organization guidance on pneumonia epidemiology, prevention, and global impact.
Centers for Disease Control and Prevention (CDC)
Clinical and public health guidance on pneumonia causes, diagnosis, treatment, and prevention.
American Thoracic Society (ATS) / IDSA Clinical Practice Guideline
Clinical practice guidelines for the diagnosis and management of community-acquired pneumonia.