Back pain is pain felt in the back. Episodes of back pain may be acute, sub-acute, or chronic depending on the duration. The pain may be characterized as a dull ache, shooting or piercing pain, or a burning sensation. The pain may radiate into the arms and hands as well as the legs or feet, and may include tingling, weakness or numbness in the legs and arms. The most common area of pain is the lower back, or lumbar area. The pain may originate from the muscles, nerves, bones, joints or other structures in the spine. Internal structures such as the gallbladder and pancreas may also refer pain to the back.
Subacute low back pain is defined as pain that lasts between 4 and 12 weeks. Chronic back pain is defined as pain that persists for 12 weeks or longer, even after an initial injury or underlying cause of acute low back pain has been treated. About 20 percent of people affected by acute low back pain develop chronic low back pain with persistent symptoms at one year. In some cases, treatment successfully relieves chronic low back pain, but in other cases pain persists despite medical and surgical treatment.