A bunion is a bony bump that forms at the base of your big toe, where the toe meets the foot. It develops when the big toe gradually angles inward toward the smaller toes while the long bone behind it (the first metatarsal) shifts outward, creating a visible protrusion on the inner edge of your foot. Bunions aren’t just a cosmetic issue. The underlying joint becomes progressively misaligned, which can lead to pain, stiffness, and difficulty finding shoes that fit.
What Happens Inside the Joint
The bump you see on the outside is really the head of the first metatarsal bone pushing against the skin. As the big toe drifts sideways and the metatarsal shifts in the opposite direction, several things go wrong at once. The joint capsule on the inner side stretches and weakens, while the tendons that normally hold the toe straight get pulled out of position. Once displaced, those tendons actually start pulling the toe further out of alignment, creating a self-reinforcing cycle of worsening deformity.
Over time, the small bones underneath the joint (called sesamoids) also shift out of place, and cartilage on the metatarsal head begins to erode from abnormal pressure. This is why bunions tend to get worse rather than better on their own. The structural changes that cause the bunion also make it progress.
Who Gets Bunions
Bunions are extremely common, especially in middle-aged and older adults. A population study of adults aged 40 to 69 found bunions in nearly 65% of those examined, with higher rates in women. About 13% of those with bunions had moderate or severe deformity.
The causes aren’t fully settled, but genetics plays a major role. Inherited foot shape, bone structure, and the way your foot distributes weight all influence your risk. Tight shoes, high heels, and narrow toe boxes have long been blamed, but research suggests they probably don’t cause bunions on their own. What ill-fitting shoes can do is accelerate the progression in someone whose foot structure already makes them susceptible. That’s an important distinction: switching to wider shoes may slow things down, but it won’t necessarily prevent a bunion if you’re genetically predisposed.
What a Bunion Feels Like
Early bunions may cause no pain at all. You might first notice the bump when shoes start feeling tighter on one side or when the skin over the joint becomes red and irritated. As the deformity progresses, common symptoms include a burning or aching sensation at the base of the big toe, swelling around the joint, and reduced range of motion in the toe. The pain often worsens with activity, particularly walking or standing for long periods.
Some people find that the big toe eventually overlaps or pushes under the second toe, making it difficult to find any shoe that doesn’t cause discomfort.
Complications of Ignoring a Bunion
Left untreated, a worsening bunion can trigger a chain of secondary problems. The most common include hammertoes, where smaller toes curl or bend abnormally as they compensate for the misaligned big toe. You may also develop pain and inflammation in the ball of the foot (metatarsalgia), or bursitis, where the fluid-filled cushioning sac near the joint becomes inflamed and swollen. Over time, chronic joint inflammation can break down cartilage and lead to arthritis.
The effects can extend beyond your foot. An altered gait from bunion pain changes the way force travels up through your legs, potentially contributing to knee, hip, or lower back problems.
How Severity Is Measured
Doctors classify bunions using X-rays to measure two angles. The hallux valgus angle (HVA) measures how far the big toe has drifted from its normal position. The intermetatarsal angle (IMA) measures the spread between the first and second metatarsal bones.
- Mild: HVA under 30 degrees, IMA under 13 degrees
- Moderate: HVA between 30 and 40 degrees, IMA between 13 and 20 degrees
- Severe: HVA over 40 degrees, IMA over 20 degrees
These measurements matter because they determine which treatments are appropriate and, if surgery is needed, which type.
Non-Surgical Options
No conservative treatment can reverse a bunion, but several approaches can slow progression and manage pain. Wider shoes with a roomy toe box reduce pressure on the bump. Padding or moleskin over the bunion protects it from friction. Ice and over-the-counter anti-inflammatory medication help during flare-ups.
Toe spacers and orthotics are popular, and there’s some evidence they can produce modest improvements. A 12-month study found that one type of orthotic reduced the bunion angle by about 5 degrees in patients with moderate bunions, a statistically meaningful change. For mild cases, orthotics reduced the angle by roughly 2 to 3 degrees, though the results were less consistent. Night splints, by contrast, showed no significant benefit after a full year of use, reducing the angle by less than 2 degrees.
The takeaway: orthotics may help slow mild to moderate bunions and provide symptom relief, but they won’t eliminate a bunion or substitute for surgery in more advanced cases.
When Surgery Becomes an Option
Surgery is typically considered when pain interferes with daily activities and conservative measures haven’t helped. The most common approach is an osteotomy, where the surgeon cuts and repositions the metatarsal bone, then uses pins or screws to hold it in its corrected alignment. Tight tendons and ligaments are released, and loose ones are tightened to stabilize the joint. Traditional osteotomy corrects the bone shift you see on an X-ray, but it has been criticized for addressing what is essentially a three-dimensional problem in only two dimensions. Bunion recurrence after this approach is relatively common.
A newer technique corrects the deformity in three dimensions by stabilizing the unstable joint at the base of the metatarsal and addressing rotation, not just the sideways drift. Because it targets the root cause of the instability, the recurrence rate is lower.
What Recovery Looks Like
After bunion surgery, you’ll wear a protective boot or surgical shoe. Depending on the procedure, you may be able to put some weight on your foot right away, or you may need crutches or a knee scooter for several weeks. Normal foot function starts returning between six and 12 weeks. Most people can get back to their usual physical activities around three months after surgery, though full healing and final results can take longer. Swelling in the surgical area sometimes lingers for several months, even after pain has resolved.