Back pain is pain felt in the back. It is divided into neck pain (cervical), middle back pain (thoracic), lower back pain (lumbar) or coccydynia (tailbone or sacral pain) based on the segment affected. The lumbar area is the most common area for pain, as it supports most of the weight in the upper body. 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. Discomfort can radiate into the arms and hands as well as the legs or feet, and may include numbness, or weakness in the legs and arms.
Back pain is common, with about nine out of ten adults experiencing it at some point in their life, and five out of ten working adults having it every year. Some estimate up to 95% of Americans will experience back pain at some point in their lifetime. It is the most common cause of chronic pain, and is a major contributor of missed work and disability. However, it is rare for back pain to be permanently disabling. In most cases of herniated disks and stenosis, rest, injections or surgery have similar general pain resolution outcomes on average after one year.
In the United States, acute low back pain is the fifth most common reason for physician visits and causes 40% of missed days off work. Additionally, it is the single leading cause of disability worldwide There are many causes of back pain, including blood vessels, internal organs, infections, mechanical, and autoimmune causes. The spinal cord, nerve roots, vertebral column, and muscles around the spine can all be sources of back pain.
The anterior ligaments of the intervertebral disc are extremely sensitive, and even the slightest injury can cause significant pain. In osteoporosis, the bones become weaker and can develop small cracks, or fractures, in the bones, resulting in pain. Arthritis in the joints of the back can also result in discomfort. The synovial joints of the spine (e.g. zygapophysial joints/facet joints) have been identified as the primary source of the pain in approximately one third of people with chronic low back pain, and in most people with neck pain following whiplash.