More than half of U.S. women have bunions, says the American Academy of Orthopaedic Surgeons (AAOS), and 9 out of 10 bunions occur in women. The main culprit for bunions is wearing tight, narrow shoes and high heels, the AAOS says. Ill-fitting shoes also can cause corns, calluses, and hammertoes.

The big toe angles inward, toward the second toe. Bunion comes from the Latin word bunio, which means enlargement. The base of the big toe gets larger and begins to extend outward. And the toe itself moves inward, sometimes even under the second toe. A bunion can affect the type of shoe you wear. The larger the bunion, the more painful it may be to walk. Over time, arthritis may develop in the joint. A bunion can also occur at the base of the little toe. This type of bunion is called a bunionette or tailor's bunion.

Many bunions can be treated by switching to shoes that fit correctly and that don't squash the toes, the AAOS says. Most bunions do not need to be corrected with surgery, particularly if they are not causing pain. A foot specialist can help you find the best treatment for your bunion and what type of shoe would be best for your foot.

That's why it is important to have your feet measured regularly. Other tips from the AAOS for buying good-fitting shoes:

• Always try on shoes to see if they fit. Don't just go by the size marked on the shoes, because shoe sizes can vary among brands.
• Measure both feet, because most people have 1 foot that is slightly larger than the other. Fit the shoe to the larger foot.
• Go shoe shopping at the end of the day, when your feet are at their largest size.
• Always stand up when you try on a shoe to make sure there is enough room for your toes. You should have at least a half-inch of space between the toe of the shoe and your longest toe. Walk in the shoe to check the fit and comfort.
• Don't buy a shoe that is too tight, assuming that the shoes will stretch with wear.

The big toe is the other common site for a corn, also called a callus. Hard corns can appear under the ends of foot bones, on the top of the toe, or on the side of the small toe. Soft corns can develop between the toes. Corns are caused by pressure and friction on the skin of your foot from ill-fitting shoes (too loose is as bad as too tight), ill-fitting socks, high-heeled shoes, or toe deformities such as a hammertoe, the AAOS says. Treatment for a corn involves changing the shoe to relieve the pressure. Pads can help if they are placed in the correct spot to relieve pressure. Sometimes you need surgery to remove the bone abnormality that is causing the corn.

First, soak the foot in warm, soapy water for about 10 minutes. Then gently remove the callus with a pumice stone, Hindu stone, or emery board, suggests the American Orthopaedic Foot and Ankle Society (AOFAS). Don't try to cut off the corn. If you have diabetes, be careful when rubbing on the corn that you don't draw blood. That could produce a sore that won't heal correctly. Most corns and calluses will go away on their own, without treatment, if the pressure that caused them stops.

This imbalance causes the tendons and joints in the toe to contract, pulling the first joint of the toe up. The bent toe looks like an upside-down V when viewed from the side. The big toe usually does not develop into a hammertoe. But all the other toes on the foot are vulnerable to this condition. A family history of hammertoes increases the risk of developing them. So does a foot injury or arthritis. Wearing shoes that are too tight can also be a cause. Hammertoes are more common in women than in men. Treatment for hammertoes usually involves switching to a shoe that doesn't aggravate the toe, or adding pads or shoe inserts. Surgery is only done as a last resort.