By ERIN ALLDAY, San Francisco Chronicle

As back pain has become an increasingly common ailment in the United States -- and for chronic sufferers, one of the most debilitating -- desperate patients and their doctors have propelled major advancements in the field.

As thousands of young, healthy athletes line up at the start of marathons this fall, the vast majority will be focused on the finish line -- not on whether they will make it there alive.

As public health experts plan for a mass immunization against the swine flu, scientists worldwide are fast-tracking research and hunting for clues that the new virus is changing and becoming more or less dangerous.

After 20 years with Type 2 diabetes, San Francisco resident Andy Chu has become mostly used to the diet restrictions required to manage the disease. He's just never going to stop missing white rice.

This nationwide recession isn't just bad for the job market, retirement plans and home sales -- it's also wreaking havoc on the country's mental health.

Steps to keeping a food diary:-- Start by deciding how to log food. Some people prefer a handheld notebook and a pen that can be pulled out anywhere, but many Web sites offer free or paid food logs. Many health care organizations also offer paper food logs to patients.

SAN FRANCISCO -- Francis Tacotaco always knew that he wasn't a particularly healthy eater. But until he started keeping a food diary and writing in painstaking, sometimes embarrassing detail about everything that went into his mouth, he didn't know just how bad it was.

It isn't unusual for doctors to hear from grateful patients -- to get cards or flowers after treating someone for cancer or saving someone in surgery.But one thank-you in particular stands out for Dr. Leah Millheiser.

When Debbie Toms first started working nights as a respiratory therapist, co-workers teased her that the graveyard shift would "take 10 years off your life," she said.It never occurred to her that there might be some truth to the statement.

Nicole Simon was 13 when she injured her knee the first time, playing soccer in a competitive girls league.She was 15 when she injured the other knee -- less than one minute into her first basketball game after recovering from the earlier injury -- and ended her athletic career before it had ever really started.