The number of pneumonia patients has increased 9 percent in the last four years, according to the country’s Health Insurance Review and Assessment Service.

The lung disease was the fifth most common cause of death for South Koreans in their 70s, and the fourth-biggest cause of death among those in their 80s.

“The statistics show that more elderly people should be informed about the disease as well as the preventive measures to take,” said the agency in a statement.

Last year, some 1.48 million pneumonia patients were treated for the disease here, while only 1.35 million sought medical treatment for the condition back in 2009.

In total, patients spent 623.1 billion won ($560 million) on treating the disease last year, about 173.8 billion won more than the total amount spent in 2009.

“The most vulnerable are children and the elderly,” said Lee Poong-hoon from the agency. “You have a greater chance of developing the condition if you have low immunity levels. And many patients don’t get treated in the early stages of the disease because they think it’s a cold or they are just feeling unwell.”

Last year, almost 50 percent of South Korean pneumonia patients were young children aged 10 or younger.

Pneumonia is an inflammatory condition of the lung affecting primarily the microscopic air sacs known as alveoli.

Symptoms include cough, fever, shivers, and sweats, on top of feeling generally unwell. Shortness of breath may occur when one climbs stairs, accompanied with a sharp pain in the side of the chest.

Those infected also usually make greenish or yellow sputum, and they can be sometimes bloodstained.

However, about 25 percent of the elderly ― those who are aged 65 or older ― show no or significantly fewer symptoms even when they develop the condition, making it difficult to diagnose in early stages.

Also, along with children, elders tend to have weaker immune systems, the agency said, and therefore often fail to fight off the infection.

And low immunity can be caused by medical treatments for serious illnesses, such as chemotherapy and an organ or bone marrow transplant.

While previously healthy individuals usually make a full recovery from pneumonia, those who are elderly or already in poor health are more likely to become seriously ill with the condition.

Pneumonia is a common cause of death in those who are already in poor health or in the final stages of terminal diseases, such as cancer.

Shim Young-soo, an official at the state agency, said it was important for children and the elderly to be immunized against the pneumococcus, the most common cause of bacterial pneumonia, as well as receive the annual flu virus vaccination, to prevent the condition.

“If you think you have symptoms that may be pneumonia, it is important to see a doctor as soon as possible,” the official said.

By Claire Lee (dyc@heraldcorp.com)