Bone spurs are smooth, bony projections that grow along the edges of bones, most often where two bones meet at a joint. When they’re close to the skin’s surface, they can appear as a visible hard lump or bump. Most bone spurs, though, are hidden deep inside a joint and only show up on an X-ray, where they look like small, pointed extensions of white bone growing outward from the normal bone edge.
What Bone Spurs Look Like on the Body
Whether you can actually see or feel a bone spur depends entirely on where it is. In joints close to the skin, like the fingers, toes, or top of the foot, bone spurs often create firm, visible bumps that don’t move when you press on them. They feel hard because they are bone. The skin over them may look slightly stretched or reddened if footwear or repeated pressure irritates the area, but the spur itself is painless to the touch in many cases.
One of the most recognizable examples is on the fingers. Osteoarthritis commonly produces small, pea-sized bony knobs on the joint closest to the fingertip. These are called Heberden’s nodes. Similar bumps can form on the middle finger joints (Bouchard’s nodes). They develop gradually over months or years and eventually become permanent, giving the fingers a knobby, widened appearance. In the early stages they may be tender and slightly swollen. Over time they harden into firm bumps that are clearly distinct from the surrounding soft tissue.
On the feet, bone spurs along the top of the foot or at the base of the big toe can create a visible ridge or bump that rubs against shoes. Heel spurs, by contrast, grow on the underside of the heel bone and are never visible from the outside. You wouldn’t know one was there without an X-ray.
In deeper joints like the shoulder, hip, knee, or spine, bone spurs are completely invisible from the surface. They may cause stiffness, pain, or reduced range of motion, but they produce no outward lump or deformity until the joint damage becomes severe enough to change the overall shape of the joint.
What Bone Spurs Look Like on X-rays
On an X-ray, bone appears bright white, and a bone spur shows up as a small white projection extending beyond the normal smooth contour of the bone. Early spurs are tiny, sometimes just a slight lip or point at the joint margin. Radiologists sometimes describe these as “lipping” because they resemble a small lip curling off the edge of the bone. Larger spurs are unmistakable: they look like pointed or rounded outgrowths, sometimes several millimeters long, jutting into the space around the joint.
Doctors use a grading system to classify how advanced joint degeneration is, and bone spur size is a key part of that assessment. In the mildest stage, spurs are so small they’re described as “doubtful” or “minute” on imaging. By the moderate stage, multiple spurs are present alongside narrowing of the joint space and early changes to the bone surface. In severe cases, spurs become large and prominent, the joint space is significantly narrowed, and the bone ends themselves may look misshapen or flattened.
The shape of bone spurs varies by location. In the shoulder, the bony roof above the rotator cuff (the acromion) can develop spurs that are flat, curved, or hooked. A hooked spur is the most problematic because it angles downward into the space where the rotator cuff tendons glide, increasing the risk of impingement and tendon damage. On a shoulder X-ray, this hook is clearly visible as a downward-pointing extension of bone.
How Bone Spurs Differ From Other Bumps
Not every hard bump near a joint is a bone spur. Ganglion cysts are fluid-filled sacs that form near joints or tendons, and they feel firm but slightly rubbery. They can sometimes be moved slightly under the skin, whereas a bone spur is completely fixed because it’s part of the bone itself. Rheumatoid nodules, which occur in rheumatoid arthritis, tend to feel firm and fleshy rather than rock-hard.
Gout can also produce visible lumps near joints called tophi, which are deposits of uric acid crystals. Tophi may look chalky or whitish under the skin and can feel gritty. They’re most common around the big toe, fingers, and elbows. A bone spur, by contrast, always feels like solid bone with no give at all.
The simplest test is pressing on the bump. If it’s immovable, hard as bone, and located right at a joint line, a bone spur is the most likely explanation, especially if you’re over 50 or have a history of osteoarthritis in that joint.
Why Bone Spurs Form
Bone spurs are your body’s attempt to stabilize a joint that’s losing cartilage. As the smooth cartilage cushion wears down, the bones experience more friction and pressure. The body responds by depositing extra bone along the joint margins, effectively trying to spread the load over a wider surface. This is why bone spurs and osteoarthritis go hand in hand: the spur is a consequence of the joint breakdown, not the cause of it.
They can also form in response to chronic tension or pulling on a bone. Heel spurs, for example, develop where the plantar fascia (the thick band on the sole of the foot) attaches to the heel bone. Years of repetitive strain cause the bone to build up at that attachment point. Similarly, spurs along the spine often form where ligaments attach to the vertebrae, particularly in people who have had years of poor posture or repetitive back strain.
When Appearance Signals a Problem
A bone spur that’s been stable for years and causes no pain generally doesn’t need treatment. Many people have bone spurs visible on X-rays taken for unrelated reasons and never experience symptoms. The spur itself isn’t dangerous.
What matters is whether the spur is pressing on something. In the spine, a spur growing into the spinal canal or a nerve exit point can compress nerves, causing radiating pain, numbness, or tingling in the arms or legs. In the shoulder, a hooked spur can fray the rotator cuff over time. In the fingers, rapidly growing nodes with redness and tenderness suggest active inflammation that may benefit from treatment.
If a bump near a joint is growing quickly, is warm to the touch, or is accompanied by fever, that pattern doesn’t fit the typical slow progression of a bone spur and warrants a closer look. Bone spurs grow over months to years, not days to weeks.