What Causes Morton’S Neuroma?

Morton’s neuroma is caused by thickening of the tissue around one of the nerves that runs between the toes, most often the nerve between the third and fourth toes. The exact trigger is not fully settled, but the leading explanation is repeated pressure or irritation of that nerve inside the narrow space between the toe bones. Over time, that irritation can lead to a swollen, thickened nerve that causes pain, burning, or numbness in the ball of the foot.

It is not a true tumor or cancer. The word “neuroma” sounds alarming, but the growth is a benign thickening of nerve tissue. Understanding what drives that thickening helps explain why certain shoes, foot shapes, and activities raise the risk.

What Causes Morton’s Neuroma?

The core cause is mechanical irritation of a nerve in the ball of the foot. The bones of the toes are connected by ligaments, and a nerve passes between them. When that nerve is squeezed or rubbed repeatedly, it can respond by swelling and forming a lump of thickened tissue.

Doctors describe this as a compression or entrapment problem. The nerve is being pinched within a tight space rather than damaged by disease. That is why symptoms often track with what a person wears on their feet and how long they spend on them.

Several factors make that pinching more likely:

• Footwear. Tight, narrow, or high-heeled shoes squeeze the toes together and shift pressure onto the ball of the foot.
• Foot shape. High arches, flat feet, or a foot that rolls inward can change how weight is distributed across the ball of the foot.
• Toe position. Bunions, hammertoes, and other toe deformities can crowd the space between the toe bones.
• Repetitive impact. Running, jumping, court sports, and jobs that involve a lot of walking or standing load the same area again and again.
• Injury. A single blow or twist to the foot can sometimes set off symptoms.

Most people who develop it have more than one of these factors working together. A narrow shoe on a foot with a high arch and a job that requires standing, for example, stacks the odds.

Why Does It Usually Affect the Third and Fourth Toes?

The third and fourth toes are the most common site because of how the foot is built. The nerve in that space is relatively thick, and the gap between the toe bones there is narrow. It also sits close to the surface, where shoe pressure lands directly.

In the second and third toe space, the nerve is smaller and better protected. That is why the same forces are less likely to irritate it. The third-and-fourth location is so typical that doctors often use it as a clue when making the diagnosis.

This is a good example of anatomy driving disease. The problem is not that this nerve is weaker than others. It is that this particular spot is more exposed to mechanical stress.

Is It Really a “Neuroma”?

Not in the strict sense. A neuroma is usually a tangle of nerve tissue that forms after an injury. The lump in Morton’s neuroma is more often a swelling of the nerve and the tissue around it, sometimes called perineural fibrosis.

This matters for how the condition is treated. Because the nerve is being compressed rather than growing a tumor, relieving the pressure is central to managing symptoms. That is why footwear changes are usually the first step doctors suggest.

The name has stuck for over a century, so it is unlikely to change. But knowing it is a compression problem, not a growth, can reduce worry. It is a benign condition.

Does Morton’s Neuroma Run in Families?

There is no clear evidence that the condition itself is inherited. What can run in families are the foot shapes and mechanics that make it more likely, such as high arches, flat feet, or a tendency toward bunions.

So if a parent had it, the shared factor is usually the shape and movement of the foot, not a gene for the nerve problem itself. That distinction is useful. It means the risk is tied to mechanics you can partly influence through footwear and activity, not a fixed genetic destiny.

What Are the Symptoms and How Is It Diagnosed?

Symptoms usually build gradually. Early on, people describe a burning or tingling in the ball of the foot that eases when they take off their shoes. Over time, the feeling can become more constant and may include numbness in the toes.

Common symptoms include:

• Pain in the ball of the foot, often described as burning, sharp, or cramping
• Tingling or numbness in the toes, usually the third and fourth
• A feeling like there is a pebble or fold in the sock under the foot
• Pain that is worse in tight shoes or during weight-bearing activity
• Relief when shoes are removed and the foot is rested

Diagnosis is usually clinical. A doctor takes a history, examines the foot, and may press on the space between the toes to reproduce the pain. Imaging such as ultrasound or MRI can help rule out other causes, but it is not always needed.

One important point: symptoms in the ball of the foot can have other causes. Nerve entrapment higher up, joint problems, and arthritis can produce similar pain. A proper exam matters because the treatment differs.

Which Conditions Are Mistaken for Morton’s Neuroma?

Several other problems can mimic it, which is why an exam is important. The most common look-alikes involve the joints, nerves, or soft tissues of the foot.

• Metatarsalgia. General pain in the ball of the foot from pressure, without a specific nerve problem.
• Tarsal tunnel syndrome. Compression of a different nerve, usually felt more toward the ankle and heel.
• Joint arthritis. Inflammation of the toe joints can cause pain in a similar spot.
• Stress fractures. Small cracks in the toe bones can cause pain that worsens with activity.
• Bursitis. Inflammation of a fluid-filled sac near the joint can produce localized pain.

These conditions can overlap, and more than one may be present. That is why self-diagnosis is unreliable here. A clinician can usually sort them out with a physical exam and, when needed, imaging.

How Is It Treated and Can It Be Prevented?

Most people improve with conservative care. The first step is usually changing footwear to something with a wide toe box and good support. Avoiding high heels and narrow shoes reduces the squeeze on the nerve.

Other common approaches include:

• Shoe inserts and padding. Metatarsal pads can offload pressure from the ball of the foot.
• Activity changes. Reducing high-impact activity while symptoms settle can help.
• Physical therapy. Stretching and strengthening may improve foot mechanics, though the evidence for it specifically in this condition is limited.
• Injections. Corticosteroid injections are used to reduce inflammation. Some clinicians also use other injectable treatments, but evidence varies and it is not established for everyone.
• Surgery. When conservative care fails, surgery to relieve pressure on the nerve or remove the affected nerve segment is an option. It is generally considered after other measures, and outcomes vary.

Prevention follows the same logic as treatment. Wide, supportive shoes, avoiding prolonged pressure on the ball of the foot, and managing foot mechanics with inserts can reduce the strain on the nerve. There is no guaranteed way to prevent it, and no single measure is proven to stop it in everyone.

One non-obvious point: padding and inserts are widely used, but the strongest evidence supports reducing pressure and irritation overall rather than any one specific product. The principle is to take load off the nerve, however that is achieved.