The most common form of arthritis, osteoarthritis, is usually associated with aging, but there can be other factors involved too, like joint injury, genetics, obesity, and even anatomic factors like joint shape and alignment. Rheumatoid arthritis is also somewhat common, but it usually affects both feet, not just one like with osteoarthritis. Rheumatoid arthritis can happen if a person's immune system attacks the lining of the membranes that surround joints. Here at Bay Area Foot and Ankle Associates, we're very familiar with arthritis, how it affects a patient, its causes, and its treatments, and we commonly see and treat patients with arthritis caused by the issues we've mentioned above, like injury and joint alignment. One of our podiatrists may refer you to a rheumatologist if they suspect rheumatoid arthritis.