Bone spurs in the spine form when your body tries to repair damaged or stressed bone and joint tissue. They’re bony projections that grow along the edges of vertebrae, essentially acting as the body’s attempt to stabilize a joint that’s wearing down. The most common driver is osteoarthritis, but several other conditions and lifestyle factors can trigger the same repair process.
How Bone Spurs Actually Form
Your spine is lined with small joints, cushioned by cartilage and separated by flexible discs. When any of these structures sustain damage, whether from years of wear or a single injury, the body launches a repair response. Part of that response involves laying down new bone tissue near the damaged area. Think of it as a bony scar: your body can’t perfectly rebuild the cartilage or disc it lost, so it deposits extra bone instead. This process is called osteophytosis.
The key point is that bone spurs aren’t a disease on their own. They’re a byproduct of something else going wrong in the joint. The spur itself is your skeleton’s attempt at a fix, even though that fix can sometimes create new problems.
Osteoarthritis: The Leading Cause
Osteoarthritis is responsible for more spinal bone spurs than any other condition. It works like this: the cartilage that cushions the facet joints (the small joints connecting each vertebra to the next) gradually breaks down over time. As that protective layer thins, the bones underneath start bearing more direct pressure and friction. Your body responds by growing new bone at the margins of the joint to spread the load across a wider surface, and those growths are bone spurs.
This process is slow, often unfolding over years or decades. Many people develop spurs without ever knowing it. Imaging studies show that by the time adults reach their mid-30s and beyond, some degree of bony overgrowth in the lumbar spine is nearly universal. In populations studied over age 35, the prevalence of detectable spurs in the lower back approached 100%.
Degenerative Disc Disease
The discs between your vertebrae are filled with a gel-like core that absorbs shock. Over time, that core loses water and shrinks. As a disc loses height, it can no longer distribute pressure evenly. The vertebrae above and below it shift closer together, which puts abnormal stress on the facet joints, surrounding ligaments, and muscles. That altered stress pattern is exactly the kind of mechanical trigger that prompts your body to build new bone.
Inside a degenerating disc, inflammatory signals ramp up and the normal balance between tissue building and tissue breakdown tips toward breakdown. The disc develops cracks and fissures, its structural proteins change composition, and it progressively loses its ability to resist compression. All of these changes cascade outward: the vertebrae respond to the new mechanical reality by reinforcing their edges with bony growths. This is why imaging of a degenerating spine so often shows both disc narrowing and bone spurs at the same level.
Age and Everyday Wear
Age is the single biggest risk factor, not because aging directly causes spurs, but because it gives osteoarthritis and disc degeneration more time to progress. Decades of bending, twisting, and bearing weight gradually wear down the cartilage and discs that protect your vertebrae. By midlife, most spines show at least some evidence of this wear on imaging, even in people who feel perfectly fine.
Excess body weight accelerates the timeline. Carrying extra pounds increases the compressive load on the lumbar spine with every step, which speeds up cartilage and disc breakdown. Occupations or sports that involve repetitive heavy lifting, prolonged vibration (like operating heavy machinery), or repeated spinal loading can have a similar effect. Construction workers, warehouse employees, and competitive athletes in high-impact sports tend to develop degenerative changes, and the spurs that accompany them, earlier than average.
Injuries and Repetitive Stress
A single traumatic event can also set the process in motion. A car accident, a fall, or a sports collision that damages a spinal joint or disc creates localized tissue injury. Your body’s repair response at that site may include depositing extra bone. This can happen even if the original injury heals well; the spur is part of the healing, not a sign that something went wrong with recovery.
Repetitive microtrauma works the same way, just more gradually. If your daily routine places the same stress on the same vertebral segment thousands of times, the cumulative effect mimics a larger injury. The tissues sustain small amounts of damage faster than they can fully recover, and the body compensates by reinforcing the area with bone.
Where in the Spine They Develop
Bone spurs can grow anywhere along the spine, but they favor the segments that bear the most load or move the most. The lower back (lumbar spine) carries the bulk of your body weight, making it the most common location for degenerative spurs. The neck (cervical spine) is the next most frequent site because it supports the head’s weight while allowing a wide range of motion. The mid-back (thoracic spine) is relatively protected by the ribcage, which limits movement and distributes stress more evenly, so spurs there are less common.
Within any given vertebra, spurs tend to grow at the edges of the vertebral body (the front-facing block of bone) or around the facet joints in the back. The location matters because it determines whether the spur is likely to cause symptoms. A spur on the front of a vertebra may never bother you. A spur that grows inward toward the spinal canal or the openings where nerve roots exit is a different story.
When Spurs Start Causing Problems
Most bone spurs in the spine are silent. They show up on X-rays or MRIs taken for other reasons and never produce symptoms. Problems begin when a spur encroaches on a space that nerves or the spinal cord need.
The spinal canal is the tunnel running through the center of your vertebrae that houses the spinal cord. The foramina are smaller openings on each side where individual nerve roots branch off. When bone spurs grow into either of these spaces, they narrow the available room, a condition called spinal stenosis. The resulting nerve compression can cause pain, numbness, tingling, or weakness in your arms (if the spur is in the neck) or legs (if it’s in the lower back). Symptoms often develop gradually and may worsen with standing or walking.
This narrowing doesn’t happen overnight. It takes years of slow spur growth combined with other age-related changes, like thickening of the ligaments inside the spinal canal, to shrink the space enough to compress a nerve. That’s why spinal stenosis from bone spurs is overwhelmingly a condition of people over 50.
Inflammatory Spinal Conditions
Not all spinal bone spurs come from mechanical wear. Inflammatory conditions that target the spine can trigger their own version of bony overgrowth. Ankylosing spondylitis, for example, causes chronic inflammation at the points where ligaments and tendons attach to the vertebrae. Over time, this inflammation prompts the body to lay down new bone along the ligaments themselves, potentially fusing vertebrae together. The bony growths in these cases look and behave differently from the garden-variety spurs of osteoarthritis, but the underlying principle is the same: the body deposits bone in response to tissue damage and inflammation.
Other inflammatory arthritis types, including psoriatic arthritis, can similarly affect the spine. These conditions tend to appear earlier in life than osteoarthritis and progress in patterns that a doctor can distinguish on imaging.
How They’re Found
Because most spinal bone spurs produce no symptoms, they’re frequently discovered incidentally during imaging for an unrelated issue. A standard X-ray can reveal spurs along the edges of vertebrae. CT scans provide more detailed views of the bony anatomy and can show exactly how far a spur extends into the spinal canal or foramina. MRI is the preferred tool when nerve compression is suspected because it visualizes both the bone and the soft tissues around it, including nerves, discs, and ligaments.
Finding a bone spur on imaging doesn’t automatically mean it’s causing your pain. Many people with prominent spurs on their X-rays have no symptoms at all, while some people with relatively small spurs in just the right (or wrong) spot experience significant nerve irritation. The clinical picture, meaning what you’re actually feeling, matters as much as what the scan shows.