Arthritis in the back develops when the joints, discs, or connective tissues of the spine break down or become inflamed. The most common cause is osteoarthritis, a gradual wearing away of cartilage in the small joints that link your vertebrae together. But several other types of arthritis can also target the spine, each with a different underlying trigger.
Osteoarthritis: The Most Common Cause
Osteoarthritis is responsible for the majority of spinal arthritis cases. It centers on the facet joints, the small paired joints that sit on the back of each vertebra and allow your spine to bend and twist. These joints are lined with smooth cartilage that lets the bones glide against each other. Over time, that cartilage degrades, leading to focal erosions that gradually spread, narrowing the joint space and hardening the underlying bone.
Once cartilage thins enough, the body tries to compensate by growing extra bone at the edges of the damaged joint. These growths, called bone spurs, can narrow the spinal canal and pinch the spinal cord or nearby nerve roots. That’s one reason back arthritis can produce not just stiffness and local pain, but also shooting pain, tingling, or numbness in the arms or legs. Because the damage is mechanical, pain from spinal osteoarthritis is typically more noticeable when you bend or twist your back and tends to ease with rest.
How Disc Degeneration Feeds Into Joint Arthritis
The discs between your vertebrae and the facet joints behind them work as a team. When a disc loses height (which happens naturally with age), the vertebrae sit closer together, changing the alignment and loading of the facet joints. That added friction accelerates cartilage loss in the facet joints, which in turn creates more bone spurs and further narrowing. This is why disc degeneration and spinal osteoarthritis so often appear together and tend to reinforce each other.
Inflammatory Types of Spinal Arthritis
Not all back arthritis comes from wear and tear. Two major inflammatory categories can affect the spine, and they behave quite differently from osteoarthritis.
Rheumatoid Arthritis
Rheumatoid arthritis is an autoimmune condition in which the immune system attacks the synovium, the thin lining inside joints. Although it more commonly hits the hands, wrists, and knees, it can also involve the cervical spine (the neck). Unlike osteoarthritis, rheumatoid arthritis isn’t caused by physical wear. It can develop at any age, and the inflammation it produces is systemic, meaning it affects the whole body rather than just the joints under the most mechanical stress.
Spondyloarthritis
Spondyloarthritis is a group of inflammatory diseases that target both joints and the spots where ligaments and tendons attach to bone. The most well-known form is ankylosing spondylitis, which primarily affects the sacroiliac joints at the base of the spine and can eventually cause vertebrae to fuse together.
Ankylosing spondylitis results from a combination of genetic and environmental factors. A gene variant called HLA-B27 significantly raises the risk, but most people who carry it never develop the disease. Studies show that about 75 percent of children who inherit HLA-B27 from a parent with ankylosing spondylitis remain unaffected. Variations in several other genes also contribute, and researchers believe environmental triggers (likely infections or gut bacteria changes) play a role, though many of these triggers haven’t been identified yet.
Inflammatory back pain has a recognizable pattern that sets it apart from mechanical pain. It typically starts gradually before age 40, improves with exercise, does not improve with rest, and often wakes people up at night. About 70 to 80 percent of people with spondyloarthritis report this pattern.
Past Injuries and Post-Traumatic Arthritis
A spinal fracture, dislocation, or severe sprain can damage the cartilage inside or around a joint. Even after the injury heals, that cartilage damage sets the stage for accelerated degeneration. This is called post-traumatic arthritis. It behaves like osteoarthritis but starts earlier and in a specific location tied to the original injury. When the resulting inflammation persists beyond six months, it’s generally considered the beginning of chronic osteoarthritis, a progressive condition where the joint continues to deteriorate over time.
How Excess Weight Damages the Spine
Carrying extra weight harms the spine through two separate pathways, and they compound each other. The first is straightforward mechanical overload. More body weight means more compression on the discs and facet joints with every step, bend, and lift. When loading repeatedly exceeds the tissue’s natural healing capacity, degeneration accelerates.
The second pathway is biochemical. Fat tissue in people with obesity enters a state of chronic low-grade inflammation, pumping out inflammatory signaling molecules. These molecules promote the breakdown of the structural matrix inside spinal discs, increase oxidative stress, and trigger cell death in disc tissue. At the same time, obesity-driven changes reduce oxygen supply to the discs and encourage abnormal blood vessel growth into areas that are normally sealed off. This breaches the disc’s natural immune barrier, allowing inflammatory cells to infiltrate and sensitize nearby pain receptors. The result is a cycle where excess weight both crushes the structure and chemically erodes it from the inside.
Occupational and Activity Risk Factors
Certain physical demands at work or in daily life speed up spinal joint degeneration. Research from the National Institute for Occupational Safety and Health identified several job-related risk factors: frequent stair climbing, prolonged standing on rigid surfaces, repetitive squatting, and jolting impacts through the legs. Jolting in particular showed a connection to cervical spine damage in a longitudinal study. Jobs involving heavy or repetitive lifting, long-haul driving over rough terrain, and high-impact sports all increase the cumulative mechanical load on spinal joints over decades.
Age, Genetics, and Other Contributing Factors
Age is the single strongest predictor of spinal osteoarthritis. Cartilage loses water content and becomes less resilient with each passing decade, and the body’s repair mechanisms slow down. Most people over 60 show some degree of facet joint degeneration on imaging, though not everyone has symptoms.
Genetics influence how quickly your cartilage wears, how your immune system behaves, and how your body handles inflammation. Family history of osteoarthritis or inflammatory arthritis raises your baseline risk. Sex matters too: women are more likely to develop rheumatoid arthritis, while ankylosing spondylitis is more common in men. Smoking, poor posture habits, and a sedentary lifestyle all reduce blood flow and nutrient delivery to spinal structures, quietly contributing to degeneration over time.
How Spinal Arthritis Is Identified
Doctors typically start with your symptom history and a physical exam. The pattern of your pain matters: mechanical pain that worsens with activity and eases with rest points toward osteoarthritis, while pain that’s worse in the morning, improves with movement, and started before age 40 raises suspicion for an inflammatory type.
X-rays can reveal joint space narrowing, bone spurs, and hardened bone, but these changes develop slowly over years. MRI is more sensitive, especially for inflammatory conditions. For spondyloarthritis, MRI can detect bone marrow swelling in the sacroiliac joints or spine well before X-ray changes appear, which is why international diagnostic guidelines now include MRI in the evaluation. Blood tests for markers like HLA-B27 or indicators of systemic inflammation help distinguish inflammatory arthritis from the degenerative type, guiding treatment in very different directions.