Bunions can be related to inflammation or to degenerative disease (e.g., osteoarthritis). They cause redness, tenderness, and pain, and alter the normal position of the first toe. Bunions worsen over time and cause discomfort, difficulty walking, and skin problems such as corns and lesions. Sometimes, a small fluid-filled sac (bursa) near the joint becomes inflamed (called bursitis), causing additional swelling, redness, and pain.

Bunions worsen over time unless the problem that produces them is eliminated. Without treatment, the deformity eventually becomes disabling.

Bunions are one of the most common foot problems. They often run in families, which suggests that the inherited shape of the foot may predispose people to them. Pronated (flat) feet are unstable and often cause bunions. Improper shoes exacerbate the underlying cause of flat, unstable feet.