"Well, I can't walk." The patient casually combed her fingers through her long brown hair as she recounted the story to the young doctors in training who surrounded the bed. "Yesterday, I tried to get out of bed and just couldn't. It hurt so much I had to sit back down. That's when I ended up here." The patient, a slender, soft-spoken woman who appeared younger than her 52 years, had dark circles under her tired eyes. Despite her offhand manner, Dr. Jennifer Quinn, a resident in her last year of training, thought the patient's pale complexion and exhausted appearance suggested a longstanding illness.