Morton's neuroma: the pebble in your shoe that is not there
Last updated September 3, 2026.
Morton's neuroma is a thickening of the nerve between the toe bones, classically between the third and fourth toes, that feels like standing on a pebble, a bunched sock, or a marble under the ball of the foot. Despite the name it is not a tumor: it is a nerve irritated and swollen by years of compression between the toe bones. It is commonest in women between 40 and 60, and shoes are usually deep in the story.
What does it feel like?
A burning or shooting pain in the ball of the foot, often radiating into the third and fourth toes, with the signature feeling of a lump or fold under the foot that nothing is there when you look. Tight or heeled shoes set it off; taking the shoe off and rubbing the foot brings relief (a classic giveaway). Some get numbness or tingling in the two toes, and a clicking feeling when squeezing the foot. It builds over months and starts limiting walks.
Why does it happen?
Compression and irritation of the interdigital nerve where it passes between the metatarsal heads: narrow toe boxes squeeze the bones together onto the nerve, high heels pitch body weight onto the ball of the foot, and activities with repetitive forefoot load (running, court sports) add to it. Foot mechanics (flat feet, bunions, tight calves) concentrate the pressure on the same spot. The thickening is the nerve's scarred response to years of this pinching.
What actually helps?
- Shoe changes first: a wide toe box, low heels, and cushioned soles; this alone settles a good share of cases and underpins everything else.
- Metatarsal pads and orthotics: a small pad placed just behind the ball of the foot spreads the metatarsal heads apart and lifts pressure off the nerve; often the single most effective trick.
- Activity tweaks: temporarily swapping forefoot-loading sport for cycling or swimming during flares.
- Steroid injection: into the tissue around the nerve; helps a large share of cases that fail shoes and pads, sometimes needing a repeat.
- Surgery: for persistent cases: removing the thickened nerve section relieves the pain reliably, at the cost of permanent numbness between the two toes, which most people consider a fair trade.
When is it an emergency?
Morton's neuroma never is. The diagnoses not to miss: a stress fracture of a metatarsal (pain and swelling on top of the foot, tender on the bone itself, after a load increase), gout or arthritis of the toe joints (hot red swollen joint), and infection of a foot wound in diabetes. Ball-of-foot pain with those features needs assessment rather than a neuroma workup. Pymander's escalation routing is built and tested specifically for this class of decision; see the safety architecture working paper.
What a Pymander AI doctor consult looks like
Illustrative example, not a real member's messages.
Common questions
Why does it feel like something is in my shoe?
Because the thickened nerve sits exactly where a pebble would: between the metatarsal heads under the ball of the foot, and each step compresses it against the ground, producing the lump or bunched-sock illusion. It is convincing enough that most people have shaken out their shoe and checked the insole before suspecting their foot. The nothing-there finding is itself diagnostic: a real lump under the foot suggests a cyst or wart, while a phantom lump that burns into the third and fourth toes points at the nerve.
Will changing shoes really make a difference?
Yes, and it is the treatment everything else builds on: the nerve is being squeezed between the toe bones, so giving the forefoot room (a genuinely wide toe box), lowering the heel (which unpitches weight off the ball of the foot), and adding cushioning directly attacks the mechanism. A meaningful share of early neuromas settle with this alone over weeks. The test is strict, though: the change has to be real (trainers or wide comfort shoes, not just lower heels) and consistent, including at home.
What is a metatarsal pad and where does it go?
A small dome-shaped pad placed just behind (not under) the ball of the foot: its job is to spread the metatarsal heads apart as you step, opening the space the nerve passes through and lifting it off the pinch point. Placement is everything, a few millimeters off and it does nothing or hurts, which is why a podiatrist fitting it the first time is worth the visit; once you feel the right spot, self-placement is easy. Combined with roomy shoes it is the most effective conservative measure.
How well do steroid injections work?
Reasonably well: around half or more of neuromas that reach injection get worthwhile relief, sometimes lasting, sometimes needing a repeat (typically up to two or three, spaced out). The injection is ultrasound-guided into the tissue around the nerve, briefly sore, and works best combined with the shoe changes. It does not shrink the thickening permanently; it quiets the inflammation around it. Failure of properly done injections plus footwear is the usual trigger for the surgical conversation.
What does surgery involve, and will my toes be numb?
The standard operation removes the thickened segment of nerve through a small incision (day case, walking in a stiff shoe straight after, a few weeks to comfortable shoes, some months to fully settled). Success rates for pain relief are high, 80% plus. The trade: because the nerve section is removed, the touching sides of the two toes are permanently numb, which nearly everyone finds trivial compared to the pain. A minority get stump regrowth pain years later, occasionally needing revision. The alternatives (releasing the ligament without nerve removal, alcohol ablation injections) exist with mixed evidence.
Can I keep running with a neuroma?
Often a modified yes: the nerve is compressed by forefoot load, so the workable formula is a wide-toe-box running shoe with forefoot cushioning, a metatarsal pad, softer surfaces, and trimmed volume, swapping some sessions for cycling or swimming during flares. Pain that forces you to stop mid-run or lingers for days after means the current setup is losing. Many runners manage mild neuromas for years this way; the ones who ignore it in narrow racing flats tend to end up in the injection-and-surgery queue sooner.