The big toe is made up of two joints. The largest of the two is the metatarsophalangeal joint (MTP), where the first long bone of the foot (metatarsal) meets the first bone of the toe (phalanx). Bunions develop at the MTP joint.

The bones of the foot and the metatarsophalangeal (MTP) joint.

A bunion forms when the bones that make up the MTP joint move out of alignment:

• The long metatarsal bone shifts toward the inside of the foot
• The phalanx bones of the big toe angle toward the second toe.
• The MTP joint gets larger and sticks out from the inside of the forefoot.

The MTP joint becomes enlarged and inflamed.

The enlarged joint is often inflamed due to both abnormal mechanics and direct irritation. The word "bunion" comes from the Greek word for turnip, and the bump on the inside of the foot typically looks red and swollen like a turnip.

Bunion Progression

Bunions start out small, but they often get worse over time. Because the MTP joint flexes with every step, the bigger the bunion gets, the more painful and difficult walking can become.

An advanced bunion changes how your foot looks.

• In severe bunions, the big toe may angle all the way under or over the second toe.
• Pressure from the big toe may force the second toe out of alignment, causing it to come in contact with the third toe. This can result in hammer toe deformities of the smaller toes.
• Calluses may also develop where the toes rub against each other, causing more discomfort and trouble walking.

Bunions often worsen over time. As the big toe angles toward the second toe, it can cross over it and cause additional problems.

Bunionette

A bunionette, or "tailor's bunion," occurs on the outside of the foot near the base of the little toe. Although it is in a different spot on the foot, a bunionette is very much like a bunion. You may develop painful bursitis and a hard corn or callus over the bump.

A bunion that forms in the main joint of the little toe is called a bunionette.

Bunions may be caused by:

• Wearing poorly fitting shoes — in particular, shoes with a narrow, pointed toe box that forces the toes into an unnatural position. Learn more: Tight Shoes and Foot Problems
• Heredity — some people inherit feet that are more likely to develop bunions due to their shape and structure. In fact, up to 70% of people who develop bunions have a family history. This suggests that genetics play a large role in whether you develop bunions. This is especially true for adolescent bunions, which develop early in life.
• Having an inflammatory condition, such as rheumatoid arthritis, or a neuromuscular condition, such as Charcot-Marie-Tooth disease or polio.

In addition to the visible bump on the inside of the foot, symptoms of a bunion may include:

• Pain and tenderness
• Redness and inflammation
• Hardened skin on the bottom of the foot
• A callus or corn on the bump
• Stiffness and limited motion in the big toe, which may lead to trouble walking

In most cases, bunions can be treated without surgery. Bunions that are not painful can be observed without any treatment at all. Although nonsurgical treatment cannot actually reverse a bunion, it can help reduce pain and keep the bunion from getting worse.

If you have bunions, it is important that your shoes fit correctly. In general:

• Choose shoes with wide insteps, broad toe boxes, soft soles, and plenty of stability.
• Avoid shoes that are too short, tight, or sharply pointed, and shoes with heels higher than a couple of inches. Higher-heeled shoes put more pressure on the forefoot and increase the chance of foot problems or injury.
• If you have pain with motion on the MTP joint, a shoe with a slight rocker bottom will be helpful.

The following tips will help you choose a shoe that fits correctly:

• Do not select shoes by the size marked inside the shoe. Sizes vary among shoe brands and styles. Judge the shoe by how it fits on your foot.
• Select a shoe that matches the shape of your foot as closely as possible.
• Have your feet measured regularly. The size of your feet changes as you grow older.
• Have both feet measured. In most people, one foot is larger than the other. Fit shoes to the largest foot.
• Try on shoes at the end of the day when your feet are the largest.
• Stand during the fitting process and check that there is enough space (3/8- to 1/2-inch) for your longest toe at the end of the shoe.
• Make sure the ball of your foot fits well into the widest part (ball pocket) of the shoe.
• Do not buy shoes that feel too tight, expecting them to eventually stretch to fit properly.
• Your heel should fit comfortably in the shoe with a minimum amount of slippage.
• Walk in the shoe before you buy it to make sure it fits and feels right. If possible, walk on different surfaces to make sure the shoe is as comfortable on a hard surface as it is on carpet.

(Left) Avoid narrow, pointed shoes that squeeze the toes. (Right) Instead, look for shoes with a roomy toe box.

Your doctor may recommend surgery for a bunion or bunionette if, after a period of time, you have pain and trouble walking after you have tried changing footwear and other nonsurgical treatments.

The goal of bunion surgery is to relieve pain by realigning the bone, ligaments, tendons, and nerves so that the big toe can be brought back to its correct position. You should only consider surgery for a bunion that is painful.

There are many surgical options to correct adult bunions. There are two main approaches for surgical correction of bunions:

• Open bunion surgery is the traditional method. The surgeon makes an incision over the bunion and removes the enlarged bony bump. The surgeon then repositions the bones using a procedure called an osteotomy. Screws or small plates are often used to hold the bones in their corrected position while they heal.
• Minimally invasive surgical (MIS) techniques have been growing in popularity among surgeons for bunions. In a minimally invasive procedure, the surgeon uses smaller incisions and specialized instruments. As with an open procedure, the surgeon usually removes the bony bump and performs an osteotomy to realign the bones. The big toe is then fixed with one or two screws to secure the repair during recovery. Depending on the technique, different types of fixation may be used.

Minimally invasive approaches may result in less early swelling and faster early recovery, though long-term outcomes are similar to traditional open techniques. MIS is not suitable for all bunions. Your surgeon will recommend the best approach and type of bunion surgery that is right for you based on your X-rays and physical exam finings.

Bunion surgery is typically performed as a same-day procedure with no hospital stay, but a long recovery is common after bunion surgery. 

Surgery to remove an adolescent bunion is not recommended unless the bunion causes extreme pain that does not improve with a change in footwear or use of orthotics. 

If an adolescent has bunion surgery, especially before reaching skeletal maturity, there is a strong chance the bunion will return. Therefore, surgery is usually delayed until growth is nearly complete to reduce the risk of the bunion coming back.

Learn more about surgery for bunions: Bunion Surgery