What is pneumonia?

Pneumonia is an infection that affects the air sacs of the lungs. The infection can be caused by a virus, by bacteria, or by other infective causes. The main symptoms are fever, cough and shortness of breath. These symptoms may begin quite suddenly, or may follow another illness, such as a cold or the flu. Medication to treat pneumonia targets the cause of infection.


People who are at increased risk of pneumonia include pregnant women, people older than 65, and people with other medical conditions. Some medical conditions, especially lung conditions and immune system conditions, make people more susceptible to pneumonia, and these people may experience recurrent pneumonias. Admission to hospital increases the risk of getting pneumonia. Viruses are a common cause of pneumonia. Bacterial causes are less common, and other causes are even rarer.


Typical symptoms include fever, cough, shortness of breath, wheezing, and chest pain. Symptoms are caused by infection and inflammation in the lungs, which causes fluid to collect in the lung sacs. These symptoms may begin quite suddenly, or may follow another illness, such as a cold or the flu.


The diagnosis is made by a doctor assessing symptoms, examining the sick person and testing phlegm (material coughed up from airways) for viruses, bacteria or other causes. X-raying the chest is often also necessary to make the diagnosis


The cause of the infection should be investigated by a doctor before starting therapy. Depending on the cause and how severe the symptoms are, the doctor may prescribe an medication. This might be an antibiotic or an antiviral medication. People with severe pneumonia may require admission to hospital for oxygen and to monitor their recovery.


Taking care to prevent the spread of colds or the flu in the home and community can help prevent some cases of pneumonia. Vaccinations can help prevent some cases of pneumonia due to certain viral and bacterial illnesses, especially in people who have other medical conditions.