The health problem that caused the sudden death of City Councilman Duke Bainum can happen to anyone, from teens to the elderly, medical experts said.

Bainum, 56, died of complications from an aortic aneurysm, Honolulu Medical Examiner Kanthi De Alwis said yesterday.

Bainum was driving home Tuesday night when he experienced chest pains and pulled over. He called 911 at about 9:30 p.m., and paramedics took him to The Queen's Medical Center, where he died around 11 p.m., said city spokesman Bill Brennan.

There were no warning signs other than chest pain, said Mallory Fujitani, a senior adviser to Bainum.

"Duke was feeling well at work yesterday and having fun chasing the kids around in the evening," Fujitani said.

The most common forms of aneurysm occur in the arteries of the brain and the heart, said Dr. Ralph Shohet, director of cardiovascular research at the University of Hawai'i's John A. Burns School of Medicine.

Aneurysms are more common in the middle-aged and elderly but can affect virtually anyone. Aortic (heart) aneurysm is usually caused by high blood pressure, smoking or high cholesterol.

An aneurysm is a weakness in the wall of an artery, and a break can cause "catastrophic bleeding" and often sudden death, Shohet said.

About 14,000 Americans die each year from aortic aneurysm, according to the National Heart, Lung and Blood Institute.

The best prevention, Shohet said, is to control blood pressure and cholesterol and, if you're a smoker, to stop smoking.

"High blood pressure is the main culprit here for nongenetic causes of aneurysm," he said.

He also suggested that people with a family history of aneurysm or Marfan Syndrome be screened for aneurysm.

Chest pains can be a sign of an aortic aneurysm, Shohet said. Other signs include pain in the jaw, neck or back; trouble breathing or swallowing; or an extreme headache, according to the institute.

"It's been described as the worst headache of your life," Shohet said.

In the event of a rupture, surgery and medicine can possibly save a patient, he said.