More than 51 million adults in the United States suffer from chronic pain, some of it completely debilitating. And increasingly, they're being referred to specialty centers known as pain clinics.

Most pain subsides after an injury heals or an illness runs its course. But with chronic pain syndrome, pain can last for months and even years after the body heals. It can even occur when there’s no ...

After developing chronic pain, I started looking into what scientists do — and still don’t — understand about the disease. Here is what I learned. By Jennifer Kahn Most of us don’t think about pain ...