LOS ANGELES, June 4 (Xinhua) -- The United States is facing a severe shortage of doctors, putting greater pressure on the country's healthcare system, the Los Angeles Times reported on Sunday.

    Twelve states, including California, have reported physician shortages and across the country patients are experiencing or soon will face shortages in at least a dozen physician specialties, including cardiology and radiology and several pediatric and surgical subspecialties, according to the paper.

    This threatens to "create a national healthcare crisis by further limiting access to physicians, jeopardizing quality and accelerating cost increases," warned the paper.

    Demand for care would explode as an aging America needs more doctors, but supply is not keeping up, said the paper. "Experts fear worsening quality and dangerously long waits for appointments."

    To meet the growing demand, medical schools have come under pressure to boost enrollment, and lawmakers have felt the urgent need to lift a cap on funding for physician training and to ease limits on immigration of foreign physicians, who already constitute 25 percent of the white-coated workforce.

    But it may be too late to head off havoc for at least the next decade, experts say, given the long lead time to train surgeons and other specialists.

    The number of medical school graduates has remained virtually flat for a quarter century, because the schools limited enrollment out of concern that the nation was producing too many doctors.

    But a healthy economy and a technology-driven boom in physicians' repertoires have driven up demand over the past recent years.

    Over the next 15 years, aging baby boomers will push urologists, geriatricians and other physicians into overdrive. Their cloudy eyes alone, one study found, could boost the demand for cataract surgery by 47 percent.

    Yet, a third of the nation's 750,000 active, post-residency physicians are older than 55 and likely to retire just as the boomer generation moves into its time of greatest medical need, according to the paper. Enditem