A bunion forms when your big toe bends toward your second toe. Often, the spot where your big toe joins your foot becomes red and callused. This area also may stick out and become hard. Bunions can form on one or both feet. They may run in the family, but most often they’re caused by wearing high-heeled shoes with narrow toes. These shoes put pressure on your big toe, pushing it toward your second toe. Felt or foam padding may help protect the bunion from irritation. Your doctor can also use a device to separate the big and second toes. If the bunion causes severe pain or deformity, you might need surgery to realign your toes.