Back pain that persists for more than three months is considered chronic. There are many potential causes of chronic back pain--the pain can result from a seemingly minor injury, or could stem from a potentially serious disease.

Injury

Injury and trauma to the back are probably the most common causes of chronic back pain. According to the National Institute of Neurological Disorders and Stroke, if the spine becomes overstressed, one of its discs may rupture or bulge outward, putting pressure on nerves and leading to pain.

Arthritis

Chronic back pain also can result from arthritis, which is increasingly common as you age. Ankylosing spondylitis is a specific, potentially serious type of arthritis that affects mainly the spine, but both rheumatoid arthritis and osteoarthritis also can cause chronic back pain.

Pregnancy

Chronic back pain is common in pregnancy, notes the American Pregnancy Association. More than half of all women experience back pain during pregnancy because of weight gain, softening ligaments and changes in their centers of gravity.

Infection

Kidney infections and kidney stones can cause chronic back pain if left untreated. Kidney-related pain often presents as tenderness above the hips, on either side of the spine, and will resolve once the infection is treated or the kidney stone passes.

Cancer

Potentially the most serious cause of chronic back pain is cancer that has spread from elsewhere in the body to the back. According to the Cleveland Clinic, cancer that has started or spread to the spine causes constant back pain that worsens at night. Cancer accounts for far fewer than 1% of all chronic back pain cases, but should be ruled out by your physician.

Source:

National Institute of Neurological Disorders and Stroke

FamilyDoctor.org

Cleveland Clinic Journal of Medicine