A bone spur on your foot typically looks like a small, hard bump or lump under the skin, though many foot bone spurs aren’t visible at all. Where you can see or feel them depends entirely on their location. Spurs on the top of the foot or near the big toe joint often create a noticeable raised area, while spurs on the bottom of the heel are usually hidden deep beneath thick tissue and only show up on an X-ray.
What You Can See and Feel From the Outside
Most people with heel spurs have no idea they have one. The spur grows on the underside of the heel bone, buried beneath layers of fat and connective tissue, so it rarely creates a visible bump. What you’re more likely to notice is localized swelling, redness, or a callus that forms over the area where the spur presses against surrounding tissue.
Bone spurs on other parts of the foot are more obvious. Spurs in the midfoot usually form on top of the foot and can appear as firm lumps or callus-covered bumps that you can both see and feel through the skin. Around the big toe joint, a spur can look like a small deformity or hard bump sitting right on top of the joint. This is common with a condition called hallux rigidus, where the joint gradually stiffens and extra bone builds up in response to wear and tear.
In all cases, the bump feels hard to the touch because it is actual bone, not fluid or soft tissue. The skin over it may look red or irritated, especially if shoes rub against it repeatedly.
What a Bone Spur Looks Like on an X-Ray
On imaging, a foot bone spur appears as a bright white projection extending from the surface of the bone. The shape varies quite a bit. Spurs are broadly categorized as either simple or irregular. Simple spurs are triangular structures that taper from a broad base to a sharp point, with smooth, well-defined borders. Irregular spurs have rougher, poorly defined edges and a less organized internal structure.
A bony projection generally needs to be larger than 2 millimeters to be classified as a true spur rather than a minor surface irregularity. Heel spurs specifically grow from the bottom of the heel bone at the point where the plantar fascia (the thick band of tissue running along the sole of your foot) attaches. On a side-view X-ray, this often looks like a small hook or thorn pointing forward toward the toes.
Size can range from a few millimeters to over a centimeter. Some spurs are barely noticeable on imaging while others are strikingly large, yet size doesn’t always predict how much pain they cause. Plenty of large spurs are painless, and some tiny ones are agonizing because of where they press on soft tissue.
How They Form
Bone spurs develop when your body tries to repair stress or damage at a joint. When cartilage wears down or a ligament pulls repeatedly on the same spot of bone, your body responds by depositing extra bone in that area. The process, called endochondral ossification, is essentially your skeleton trying to reinforce a weak point. Over months or years, those deposits harden into a spur.
On the heel, this commonly happens where the plantar fascia connects to the heel bone. Chronic tension from standing, running, or carrying extra weight gradually irritates that attachment point, and the body lays down calcium in response. In the midfoot and toes, spurs tend to develop around joints where cartilage has broken down from arthritis or repetitive motion.
Bone Spur vs. Bunion
Because both can appear as a bump near your big toe, bone spurs and bunions are easy to confuse. The key difference is what’s happening underneath. A bunion is a structural misalignment: the big toe angles inward toward the other toes, pushing the joint outward and creating that characteristic bump on the inner side of the foot. A bone spur is extra bone growth, typically forming on top of a joint rather than at the side.
Both can cause redness, swelling, and pain that worsens with tight shoes. But bunions involve a shift in the position of the toe itself, which you can usually see clearly. With a bone spur, the toe stays aligned while a hard lump develops over the joint surface. Bone spurs also tend to limit the joint’s range of motion more than bunions do, particularly at the big toe, where bending the toe upward may become noticeably difficult or painful. Bone spurs can vary considerably in size and are often more painful than bunions of similar appearance.
Where Foot Bone Spurs Commonly Appear
- Bottom of the heel: The most common location. Rarely visible from outside, often discovered only after heel pain prompts an X-ray. The spur grows where the plantar fascia attaches to the heel bone.
- Top of the midfoot: These spurs can form visible or palpable lumps on the top of the foot, sometimes with a callus developing over them from shoe pressure.
- Big toe joint: Associated with hallux rigidus, these appear as a bump on the top of the joint. The toe gradually loses flexibility as the spur grows.
- Back of the heel: Known as a pump bump, this develops where the Achilles tendon meets the heel bone. It’s often visible as a hard lump at the back of the heel that rubs against the shoe counter.
When a Bump Needs a Closer Look
If you notice a hard bump on your foot that doesn’t go away, getting an X-ray is the only reliable way to confirm whether it’s a bone spur. Many bumps on the foot turn out to be something else entirely: ganglion cysts (fluid-filled sacs that feel firm but slightly squishy), bursitis (inflamed cushioning tissue), or simply a callus with no underlying bone change. A bone spur will feel rock-hard and fixed in place because it’s literally part of the bone.
Pain that worsens with activity, stiffness in a toe joint, or a bump that steadily grows over several months are all patterns consistent with a bone spur. The spur itself isn’t always the source of pain. Often it’s the inflammation in the surrounding soft tissue that hurts, which is why some people have visible spurs on X-ray with zero symptoms while others with smaller spurs can barely walk.