Hallux valgus is the medical term for a bunion, a progressive foot deformity where the big toe angles inward toward the smaller toes while the bone behind it shifts outward, creating a bony bump on the inside of the foot. It affects roughly 1 in 5 people worldwide, and about twice as many women as men. While it starts as a cosmetic concern for many, it can gradually cause significant pain, alter the way you walk, and create problems in neighboring toes.
What Happens Inside the Foot
Your big toe connects to the rest of your foot at the first metatarsophalangeal joint, a hinge where the long bone of the foot (the first metatarsal) meets the first bone of the toe. In hallux valgus, the metatarsal drifts toward the inner edge of the foot while the big toe angles toward the outer edge. This creates a widening V-shape at the joint, and the bony prominence you see on the side of the foot is the exposed head of that metatarsal.
Once the toe starts shifting, the tendons that normally pull it straight begin pulling at an angle instead, which reinforces the deformity. The further the joint displaces, the more mechanical advantage these tendons gain in the wrong direction. Tension on the inner side of the joint stimulates new bone growth (that’s the bump getting bigger), while structures on the outer side lock into a displaced position. This self-reinforcing cycle is why bunions rarely correct themselves and tend to worsen over time.
Who Gets Bunions
A large meta-analysis covering over 186 million people found an overall prevalence of about 19%. Women are affected at nearly double the rate of men: roughly 24% versus 11%. Age plays a clear role too. About 11% of people under 20 show signs of hallux valgus, that number stays around 12% through middle adulthood, then jumps to nearly 23% in people over 60.
Causes and Risk Factors
Bunions don’t have a single cause. They develop from a combination of inherited foot structure, how your foot moves, and what you put on it.
Genetics and Foot Structure
Family history is one of the strongest predictors. Research has identified mutations in genes related to collagen and connective tissue that appear to run in families with high rates of bunions. Variations in vitamin D receptor genes have also been linked to higher risk. In practical terms, if your parents or grandparents had bunions, you’re more likely to develop them. What you inherit isn’t the bunion itself but the foot shape and tissue flexibility that set the stage for one. A longer big toe, excessive flexibility in the first metatarsal joint, flat feet, and weak muscles along the inner arch all increase the likelihood. Flat feet in particular are associated with more severe deformities.
Footwear
Shoes with narrow toe boxes are a well-documented contributor, especially when worn consistently during younger years. One study found that people who wore shoes with tight toe boxes during their 20s and 30s were 2.7 times more likely to develop hallux valgus. Historical research paints the same picture: populations that wore tight, pointed shoes had significantly higher bunion rates than barefoot populations. Even in children, footwear that doesn’t leave enough room for the toes is associated with higher angles of deviation at the big toe joint.
Symptoms and How Bunions Progress
The earliest sign is usually the visible bump itself, which may not hurt at all. As the deformity progresses, the most common symptom is a burning pain or tingling over the bump, caused by nerve irritation from pressure, often from shoes pressing against the prominence. Redness and fluid-filled swelling (bursitis) over the bump are signs of ongoing friction.
Many people notice problems beyond the bunion before they notice the bunion itself. As the big toe crowds into the second toe, that second toe can develop a hammertoe, curling upward at the middle joint. Calluses form between the toes or under the ball of the foot. Up to half of people with hallux valgus experience pain under the second and third metatarsal heads, a condition called transfer metatarsalgia, because the shifted big toe no longer carries its share of your body weight during walking.
Progression is typically slow, unfolding over years. Pain often starts as occasional and activity-related, then gradually becomes more frequent and intense. Some people notice a period where the bump seems to grow more quickly. If the second toe is unstable or hypermobile, it can’t act as a brace against the drifting big toe, and the deformity may advance faster. In long-standing cases, the tendons on top of the big toe can contract permanently, making the joint stiff as well as crooked.
Non-Surgical Treatment Options
Conservative treatment can’t reverse a bunion, but it can slow progression and reduce pain. The best evidence supports a combination approach. A network meta-analysis comparing different non-surgical strategies found that exercise combined with toe separators, night splints, and targeted soft-tissue therapy were the most effective options for reducing the angle of deviation at the big toe joint. Toe separators, whether used alone or alongside strengthening exercises, also ranked highly for improving how patients felt day to day.
In practical terms, this means wearing silicone spacers between the big and second toe during the day, doing exercises to strengthen the muscle that pulls the big toe away from the others (you can practice spreading your toes apart against resistance), and wearing a splint at night to hold the toe in a straighter position. Switching to shoes with a wide, round toe box is one of the simplest and most effective changes you can make. Padding over the bump and custom orthotics to support the arch can also reduce pressure and pain. These measures work best for mild to moderate bunions. The evidence for long-term structural correction from conservative care alone is limited.
When Surgery Becomes an Option
Surgery is considered when pain persists despite conservative measures, when the deformity is severe enough to interfere with daily activities, or when secondary problems like hammertoes or chronic metatarsalgia develop. There is no single bunion surgery. The procedure your surgeon recommends depends on how severe the deformity is and where the instability originates.
For mild to moderate bunions, the most common approach is a distal osteotomy, where the surgeon cuts and repositions the head of the metatarsal bone closer to the toe joint. The chevron osteotomy is a widely used version of this. For moderate to severe bunions with a wider angle between the first and second metatarsals, a proximal osteotomy or a scarf osteotomy (a Z-shaped cut along the shaft of the bone) allows for greater correction. In the most severe cases, or when the joint at the base of the metatarsal is unstable, a Lapidus procedure fuses that base joint to eliminate the source of the drift entirely.
Recovery After Bunion Surgery
Recovery timelines vary by procedure, but a minimally invasive correction offers a useful benchmark. For the first two weeks, you’ll bear weight only on your heel and use crutches. After a two-week check, most people can begin putting full weight on the foot. You’ll wear a flat orthopedic shoe for about five weeks total. At five weeks, you can transition to a regular shoe with a firm, flexible sole and good coverage over the front of the foot.
Driving and low-impact exercise like swimming or cycling typically resume around six weeks. High-impact activities, including running and court sports, are generally cleared at three months. Full recovery with final swelling resolution can take six months to a year, depending on the extent of the procedure.
Potential Complications
Left untreated, hallux valgus commonly leads to hammertoe deformity of the second toe, painful calluses, and transfer metatarsalgia, where the ball of the foot aches because weight has shifted off the big toe. Surgery carries its own risks. About 5% of patients develop a malunion where the bone heals in a slightly elevated position, which can cause continued metatarsalgia. Overcorrection, where the big toe ends up pointing too far inward (called hallux varus), occurs in roughly 6% of surgical cases. These complications are generally manageable but underscore why the decision to operate should weigh the severity of symptoms against the recovery commitment.