The Mayo Clinic explains that bone spurs are simply an extra bone on top of the foot. According to WebMD, these spurs occur when the bone tries to repair itself by building extra bone, and they also form in response to pressure, rubbing and stress that occur over a long period of time.
Also known as osteophytes, bone spurs primarily form from the wear and tear that comes with osteoarthritis. As WebMD explains, bone spurs sometimes occur as a natural part of aging. The site goes on to state that the discs that provide cushioning between the bones of the spine may break down with age. This leads to pain and swelling, and in some cases, bone spurs form along the edges of the joint over time. WebMD further states that bone spurs form from other causes, such as tight ligaments and as a result of activities like dancing and running that put pressure on the feet. They may also form when people wear poorly fitting shoes.
The Mayo Clinic explains that people may not detect this condition for years and that the condition may not merit treatment. However, bone spurs may break off from the larger bone and float into the joints.