Definition

Morton neuroma is painful thickening of the tissue around one of the nerves in the foot. It can affect any of the toes in the foot. However, it most often affects the nerves that run between the third and fourth or between the second and third toes.

Nerves of the Foot Copyright © Nucleus Medical Media, Inc.

Causes

The thickening of the nerve caused by inflammation and the build-up of fibrous tissue on the nerve's outer coating. This fibrous build-up is a reaction to the irritation resulting from nearby bones and ligaments rubbing against the nerves.

Irritation can be caused by:

• Wearing shoes that are too tight
• Wearing shoes that place the foot in an awkward position, such as with high heels
• A foot that is mechanically unstable
• Repetitive trauma to the foot such as from sports activities like tennis, basketball, and running
• Trauma to the foot caused by an injury such as a sprain or fracture

It is unusual for more than one Morton neuroma to occur on one foot at the same time. It is rare for Morton neuroma to occur on both feet at the same time.

Risk Factors

Morton neuroma is more common in women. Other factors that may increase your chance of Morton neuroma include:

• Wearing narrow and/or high-heeled shoes
• Obesity
• Injuries to the foot
• Activities that cause repetitive trauma to the foot such as sports-related activities

Symptoms

Morton neuroma may cause:

• Burning, pain, tingling, and numbness often shooting into the toes
• Discomfort that is worse while walking
• Feeling of a lump between the toes
• Symptoms are usually temporarily relieved when:
  • Taking off the shoes
  • Flexing the toes
  • Rubbing the feet

Diagnosis

The doctor will ask about your symptoms and medical history. A physical exam will be done. Initial diagnosis of Morton neuroma is based on your description of the type and location of pain and discomfort in the foot. The diagnosis will be confirmed by:

• Physical exam of the foot, including:
  • Checking for mechanical abnormalities in the foot
  • Squeezing the side of the foot, which will usually cause pain when Morton neuroma is present
• Examination of your shoes to:
  • Check for excess wear in parts of the shoe
  • Check to see whether the shoes are too tight

Imaging tests evaluate the foot and surrounding structures. This may be done with:

• X-ray
• MRI scan
• Ultrasound

Injections of local anesthetic can also be used for diagnosis

Treatment

Treatments may include:

Prevention

To help reduce your chance of Morton neuroma:

• Avoid wearing tight and/or high-heeled shoes.
• Maintain or achieve ideal body weight.
• If you play sports, wear roomy, properly fitting athletic footwear.