Back pain can come on suddenly and last less than six weeks (acute), which may be caused by a fall or heavy lifting. Back pain that lasts more than three months (chronic) is less common than acute pain.

Back pain often develops without a specific cause that your doctor can identify with a test or imaging study. Conditions commonly linked to back pain include:

  • Muscle or ligament strain. Repeated heavy lifting or a sudden awkward movement may strain back muscles and spinal ligaments. If you're in poor physical condition, constant strain on your back may cause painful muscle spasms.
  • Bulging or ruptured disks. Disks act as cushions between the bones (vertebrae) in your spine. The soft material inside a disk can bulge or rupture and press on a nerve. However, you can have a bulging or ruptured disk without back pain. Disk disease is often found incidentally when you undergo spine X-rays for some other reason.
  • Arthritis. Osteoarthritis can affect the lower back. In some cases arthritis in the spine can lead to a narrowing of the space around the spinal cord, a condition called spinal stenosis.
  • Skeletal irregularities. Back pain can occur if your spine curves abnormally. Scoliosis, a condition in which your spine curves to the side, also may lead to back pain, but generally only if the scoliosis is severe.
  • Osteoporosis. Your spine's vertebrae can develop compression fractures if your bones become porous and brittle.
June 17, 2015