It is important to understand that back pain is a symptom of a medical condition, not a diagnosis itself. Medical problems that can cause back pain include the following:
Mechanical problems: A mechanical problem is due to the way your spine moves or the way you feel when you move your spine in certain ways. Perhaps the most common mechanical cause of back pain is a condition called intervertebral disc degeneration, which simply means that the discs located between the vertebrae of the spine are breaking down with age. As they deteriorate, they lose their cushioning ability. This problem can lead to pain if the back is stressed. Another cause of back pain is the wearing down of the facet joints, which are the large joints that connect each vertebrae to another. Other mechanical causes of back pain include spasms, muscle tension, and ruptured discs, which are also called herniated discs.
Injuries: Spine injuries such as sprains and fractures can cause either short-lived or chronic back pain. Sprains are tears in the ligaments that support the spine, and they can occur from twisting or lifting improperly. Fractured vertebrae are often the result of osteoporosis, a condition that causes weak, porous bones. Less commonly, back pain may be caused by more severe injuries that result from accidents and falls.
Acquired conditions and diseases: Many medical problems can cause or contribute to back pain. They include scoliosis, which causes curvature of the spine and does not usually cause pain until mid-life; spondylolisthesis; various forms of arthritis, including osteoarthritis, rheumatoid arthritis, and ankylosing spondylitis; and spinal stenosis, a narrowing of the spinal column that puts pressure on the spinal cord and nerves. While osteoporosis itself is not painful, it can lead to painful fractures of the vertebrae. Other causes of back pain include pregnancy; kidney stones or infections; endometriosis, which is the buildup of uterine tissue in places outside the uterus; and fibromyalgia, which causes fatigue and widespread muscle pain.
Infections and tumors: Although they are not common causes of back pain, infections can cause pain when they involve the vertebrae, a condition called osteomyelitis, or when they involve the discs that cushion the vertebrae, which is called discitis. Tumors, too, are relatively rare causes of back pain. Occasionally, tumors begin in the back, but more often they appear in the back as a result of cancer that has spread from elsewhere in the body.
Although the causes of back pain are usually physical, it is important to know that emotional stress can play a role in how severe pain is and how long it lasts. Stress can affect the body in many ways, including causing back muscles to become tense and painful. Untreated depression and anxiety can make back pain feel much worse. Likewise, insomnia, or the lack of sleep, can also contribute to back pain.