What Causes Bunions?

Family history plays a role but is not the sole cause

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A bunion is a large, bony bump that forms on the metatarsal bone. This prominence develops in response to hallux valgus, a condition in which the first toe gradually migrates toward the second toe. As the big toe becomes more and more deformed, the bunion grows more prominent in size.

Ultimately, bunion pain can develop if the prominence becomes compressed by narrow shoes or begins to alter how you walk.

This article will detail how bunions form, who is likely to get them, and how they are typically treated.

bunions on feet

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How Bunions Form

Bunions start off small in size and gradually become larger as time goes on. They form as a result of hallux valgus, which is actually a combination of these two big-toe deformities:

  • The first metatarsal bone (the bone at the base of the big toe) shifts medially, toward the other foot.
  • The big toe (hallux) shifts laterally, toward your other toes.

As these changes occur, a bunion begins to develop on the inner base of the affected big toe.

Bunions and Overlapping Toes

Bunion Subtypes

While the most common type of bunion is described above, several other subtypes can occur. These include:

  • Tailor’s bunion (bunionette): This type of bunion occurs when the bone at the base of the fifth (smallest) toe (called the fifth metatarsal bone) shifts outward as the little toe migrates inward. This causes a prominence to develop on the outer base of the little toe.
  • Juvenile bunion or juvenile hallux valgus: This version of a bunion is seen in children, most commonly females age 10 to 15. This type of bunion is commonly associated with hypermobility in the joints of the foot and can affect stability and function.

What Makes You More Likely to Get Bunions?

The reason for bunion deformity has multiple factors—both biomechanical and physiologic. Sometimes, more than one factor is occurring in a single person. These can include:

  • Types of shoe gear and fit
  • Body type
  • Ligament structure and integrity
  • Foot structure
  • Familial history that aligns with your body type/foot structure and ligaments
  • Some systemic conditions like arthritis

Bunion Prevention

If you have a family history of bunions, wearing shoes with a wide toe box, a low heel, and good arch support could help you avoid developing this condition.

What Causes Bunion Flares?

Just because you have a bunion does not necessarily mean that you will have pain. In fact, many people with small bunions experience minimal (if any) symptoms. As the bump becomes more pronounced, however, certain types of activities may lead to bunion pain or inflammation. Among the most common causes of a flare-up are:

  • Compression or rubbing of the bunion against a narrow-toed shoe
  • Extended walking, particularly on inclines
  • Running or other high-impact forms of exercise

Going Barefoot

Barefoot walking does not commonly cause bunion flare-ups. In fact, going barefoot may actually strengthen the muscles in the foot and alleviate any compression-caused symptoms.

Treating Bunion Pain

If you are experiencing a bunion flare-up, there are several at-home treatments that may provide you with some relief. These include:

  • Switching to shoes with a wide toebox
  • Using felt or cushions in your shoe to reduce bunion compression
  • Placing a spacer between the first and second toes on the affected foot
  • Wearing an orthotic (a shoe insert) to provide arch support if you have flat feet
  • Consistently stretching your calf muscles to reduce the strain on the forefoot
  • Taking nonsteroidal anti-inflammatory drugs (NSAIDs), such as Advil or Motrin (ibuprofen) or Aleve (naproxen sodium) to alleviate pain and inflammation
  • Doing foot exercises to increase the mobility of your toes

The evidence supporting many of these interventions is still somewhat questionable. In addition, it is important to note that while these treatments may reduce the pain you are experiencing, they will not shrink or stop your bunion from growing.

Bunion Surgery

The only way to reverse a bunion and restore the natural angle of the big toe is to have the deformity surgically corrected. More than 100 different surgical techniques can be used to address this condition. Factors like the degree of toe deformity and osteoarthritis in the toe often dictate which method is chosen.

Following the procedure, you may be required to go through a period of non-weight-bearing (not putting weight on the foot) or wearing a hard-soled shoe for several weeks. Physical therapy is also typically ordered to help improve movement in the big toe and restore a normal walking pattern.

Indications for Bunion Surgery


Surgery is rarely performed for cosmetic reasons. Instead, it is usually only indicated if a bunion is causing pain or limiting your daily function.

Summary

A bunion is a bony prominence that occurs on the metatarsal bone. This issue develops due to hallux valgus, a deformity in which the big toe pushes against the second toe. Women, older individuals, people with a family history of bunions, and those frequently wearing narrow-toed shoes are more predisposed to this issue.

Conservative treatments like NSAIDs, toe spacers, and shoe inserts or padding may help alleviate bunion flare-ups.

5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. American Academy of Orthopaedic Surgeons. Bunions.

  2. Ray JJ, Friedmann AJ, Hanselman AE, et al. Halluxvalgus. Foot & Ankle Orthopaedics. 2019;4(2):247301141983850. doi:10.1177/2473011419838500

  3. Columbia University. Bunions.

  4. Penn Medicine. What is bunion (hallux valgus). Updated June 8, 2022.

  5. Fraissler L, Konrads C, Hoberg M, Rudert M, Walcher M. Treatment of hallux valgusdeformity. EFORT Open Reviews. 2016;1(8):295-302. doi: 10.1302/2058-5241.1.000005

By Tim Petrie, DPT, OCS
Tim Petrie, DPT, OCS, is a board-certified orthopedic specialist who has practiced as a physical therapist for more than a decade.