Many disorders are associated with spinal anatomy. Some are congenital (present at birth). However, most are acquired, due more often to cumulative physical stress or aging than to sudden trauma. Disorders of the spine include:

• Herniated disc. A frequently painful condition in which the cartilage of an intervertebral disc bulges through its protective covering and can press on a nerve. This causes pain that often begins in the back or neck and sometimes extends down a limb. Herniated discs are common causes of pinched nerves and sciatica.

• Degenerative disc disease. A condition, associated with aging, in which the intervertebral discs deteriorate and can press upon nerves, causing pain.
  
  
• Spinal stenosis. A narrowing of space inside the spine that causes compression of the spinal cord or nerve roots. It typically develops later in life as a result of degenerative changes in the spine that occur with aging.
  
  
• Osteoporosis. A degenerative bone condition, associated with aging, that typically affects the spine and can involve vertebral fractures.

• Whiplash and other causes of neck pain.
  
  
• Facet (zygapophysial) joint pain. Pain in the joint between two vertebrae. Facet joints are one of the common sites of neck and back pain, especially after a whiplash injury.
  
  
• Spinal cord injury (SCI). Most cases of SCI involve sudden trauma, such as from a motor vehicle accident, diving accident or gunshot wound, that dislocate or fracture vertebrae. Depending on the severity and location, SCI may cause permanent paralysis or result in a partial or nearly complete recovery of motor function and sensation.
  
  
• Ankylosing spondylitis. A form of arthritis that primarily affects the spine.
  
  
• Other forms of arthritis. Osteoarthritis often affects the spine. Rheumatoid arthritis sometimes restricts movement in the cervical spine. Reiter’s syndrome (reactive arthritis) often causes pain in the lumbar spine. Juvenile arthritis may affect the spine in children.
  
  
• Paget’s disease. Skeletal disease in which bone is broken down and replaced with oversized but weakened tissue. This can compress the spinal cord or nerve roots, resulting in excruciating pain that may radiate down into the legs.
  
  
• Meningitis. Inflammation of the meninges, the membranes that cover the spinal cord and brain. Viral or bacterial infections cause most cases of meningitis.
  
  
• Spondylolysis. A stress fracture in a posterior vertebral area called the pars interarticularis. This usually affects the fifth (lowest) lumbar vertebra and is a common source of low back pain in school-age athletes but can affect anyone. Sometimes the damaged vertebra becomes so weak it slips out of place, a condition known as spondylolisthesis.
  
  
• Scoliosis. An abnormal sideways curvature of the spine. Scoliosis is usually painless but can result in chronic back pain and other complications if left untreated.

• Spina bifida. A birth defect in which part of the vertebral column fails to close. Many cases are caused by a deficiency of folic acid, a B vitamin. Surgery can often treat spina bifida. Some mild forms (spina bifida occulta) produce no symptoms and may never be identified.
  
  
• Achondroplasia. Genetic disorder that slows the rate of bone formation during fetal development and in early childhood. Patients have a shortened stature, including a smaller spinal canal that pressures the spinal cord. This can cause severe back and leg pain and paralysis of the legs.
  
  
• Neurofibromatosis. A genetic disorder that causes noncancerous (benign) tumors to develop on nerves in the eyes, ears, brain, spinal cord and limbs. Many cases are mild and do not require treatment. Neurofibromatosis may cause scoliosis.
  
  
• Other tumors. Benign tumors or cancer, such as those of the spinal cord, meninges, brain or bones, may affect the spine.
  
  
• Syringomyelia. Formation of a cyst (syrinx) within the spinal cord. MRI has improved early diagnosis of this disorder.
  
  
• Ossification of the posterior longitudinal ligament. Occurs when calcium deposits turn fibrous tissue into bone on the ligament running up and down the spine inside the spinal canal. These deposits may cause pain if they press on the nerves of the spinal canal. 
  
  
• Skeletal fluorosis. Immobilization of the spine and joints due to high levels of fluoride in the body. This makes any kind of movement painful. Skeletal fluorosis usually results from long-term inhalation of industrial dusts or gases contaminated with fluorides, long-term consumption of water containing large amounts of fluoride and accidental ingestion of insecticides that contain fluoride. It is rare in the United States.