What is pneumonia?

SINGAPORE - Pneumonia is an infection of the lungs, usually caused by bacteria or a virus. In severe cases, it can result in respiratory failure, and the patient will require mechanical ventilation to help him breathe.

The ventilator takes over the breathing function of the lungs and gives the medication - such as antibiotics, in the case of a bacterial infection - time to work and the body time to recover.

Antibiotics usually take about two to three days to become effective. Dr Lee Yeow Hian, a respiratory physician and internist in private practice, said about four out of five patients with severe pneumonia recover and go home.

But there could be some damage to the lungs that could cause breathlessness.

Patients who remain on a ventilator for weeks also risk getting another bug from the equipment - called ventilator acquired pneumonia - that could prolong the illness.

Dr Lee, who has clinics at Mount Elizabeth Novena Hospital and Mount Alvernia Hospital, said patients can get two bouts or more of the disease from different bugs. They could get pneumonia caused by a virus, and in their weakened state, catch a bacterial infection.

He said how well a person does depends on various factors, such as how fit the person is to start with, and how aggressive the bug causing the pneumonia is.

He added that so long as the patient remains on life support, the condition is considered critical, as "things can change very fast".

According to the Health Ministry, nearly one in five deaths in 2013 was caused by pneumonia, the second-highest cause of death in Singapore after cancer.

The Health Promotion Board recommends that people aged 65 and above get vaccinated for pneumococcal pneumonia, which is one of the most common bacteria causing pneumonia.

This article was first published on February 22, 2015.
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