Pneumonia is an infection of one or both of the lungs caused by bacteria, viruses, or fungi. It is a serious infection in which the air sacs fill with pus and other liquid.

What causes pneumonia?

The main types of pneumonia are :

Bacterial pneumonia : This type is caused by various bacteria. The most common is Streptococcus pneumoniae. It usually occurs when the body is weakened in some way, such as by illness, poor nutrition, old age, or impaired immunity, and the bacteria are able to work their way into the lungs. Bacterial pneumonia can affect all ages, but you are at greater risk if you abuse alcohol, smoke cigarettes, are debilitated, have recently had surgery, have a respiratory disease or viral infection, or have a weakened immune system.

Viral pneumonia : This type is caused by various viruses, including the flu (influenza), and is responsible for about one-third of all pneumonia cases.

How is pneumonia diagnosed?

Diagnosis is usually made based on your recent health history (such as surgery, a cold, or travel exposures) and the extent of the illness. Based on these factors, your healthcare provider may diagnose pneumonia simply on a thorough history and physical exam.

The following tests may be used to confirm the diagnosis :

Bronchoscopy : This is direct exam of the bronchi (the main airways of the lungs) using a flexible tube (called a bronchoscope). It helps to evaluate and diagnose lung problems, assess blockages, and take out samples of tissue and/or fluid for testing.

Pleural fluid culture : In this test, a sample of a fluid sample is taken from the pleural space.

How is pneumonia treated?

Treatment depends on the type of pneumonia you have. Most of the time, pneumonia is treated at home, but severe cases may be treated in the hospital.

Antibiotics are used for bacterial pneumonia.

Can pneumonia be prevented?

Check with your healthcare provider about getting immunizations. The flu is a common cause of pneumonia. Because of that, getting a flu shot every year can help prevent both the flu and pneumonia.

Pneumococcal Vaccine : It will protect you from a common form of bacterial pneumonia. Children younger than age 5 and adults ages 65 and older should get this shot.

The pneumococcal shot is also recommended for all children and adults who are at increased risk of pneumococcal disease due to other health conditions.