Pneumonia: Disease at a Glance

Pneumonia is an inflammatory condition of the alveoli (or air sacs) of the lungs. The infection can be caused by a bacteria, virus or fungi. It’s important to understand the cause of pneumonia, because the treatment depends on the cause.


When the alveoli become inflamed and fill up with fluid, it causes symptoms like chest pain during deep breath, chills with shivering, fever, cough and difficulty in breathing. Symptoms may vary from mild to severe.


Pneumonia can be classified into two types, depending on how the lung is affected – lobar pneumonia (in which a large area of the lobe or section of a lung is affected) and bronchopneumonia (in which both lungs are affected in patches).


Lobar Pneumonia


Usually infects healthy individuals between  30-50 years Mostly seen in infants, elderly & those with weak immunity
Disease onset is sudden  Disease onset is insidious
Symptoms: High fever, chill with shivering, rusty or bloody sputum Symptoms: Low-grade fever,  productive cough of purulent sputum


Lobar pneumonia undergoes an acute progression in four stages. The first stage is congestion, occurring within the first 24 hours, when the lung is heavy as well as congested.


The next stage is consolidation, wherein the airspaces are filled with secretion, giving the affected area an appearance of solidification or consolidation. The third stage is grey hepatisation, where the alveoli still appear to be consolidated but the colour is paler and drier. The last stage is resolution or complete recovery.


Pneumococcus bacteria causes lobar pneumonia is most cases. On the other hand, staphylococcus bacteria, streptococcus bacteria and H.Influenzae bacteria cause bronchopneumonia.


Lobar pneumonia usually infects healthy individuals between 30-50 years, while bronchopneumonia is mostly seen in infants, elderly and those suffering from chronic debilitating diseases.


The onset of the disease in lobar pneumonia is sudden and is characterized by high fever, chill with shivering and rusty or bloody sputum. In the case of bronchopneumonia, the onset is insidious with low-grade fever and productive cough of purulent sputum.


Complications of lobar pneumonia include meningitis, endocarditis and arthritis. In the case of bronchopneumonia, the complications include fibrosis of the lungs, bronchiectasis and lung abscess. 


Antibiotics are usually prescribed for pneumonia treatment; patients are also advised to take rest and good nutrition. Preventive measures against pneumonia include vaccination, environmental measures and suitable treatment of other health problems.



1. American Lung Association (
2. US National Library of Medicine (
3. NHS Choices (
4. World Health Organization (


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