What is Morton's neuroma?

A Morton's neuroma is inflammation (swelling), thickening, or enlargement of the nerve between the bones of the toes (metatarsal bones). The condition is also called intermetatarsal neuroma.

The thickening is usually found between bones of the third and fourth toes of the foot, but often can develop between the second and third toes, as well. It occurs when the nerve becomes compressed (squeezed) or irritated, possibly because the metatarsal bones press against the nerve in the narrow gap between the toes.

If it is not treated, a plantar interdigital neuroma can cause a sharp, burning, or shooting pain that often gets worse over time. The pain becomes worse when a person walks or stands on the ball of the foot or wears higher-heeled shoes. Pain can spread into the nearby toes, and can give the feeling of a bunched-up sock.

Who gets Morton's neuroma?

People who are born with flat feet, high arches, or an abnormal position of the toes are more prone to developing Morton's neuroma. This may be due to instability around the toe joints. Certain conditions that develop over time, such as bunions or hammer toes, are also associated with Morton's neuroma. Some sports that involve running, including tennis and other racquet sports, and the elliptical forces, increase pressure on the ball of the foot, and can also increase the chance of developing Morton's neuroma due to trauma or injury to the foot.

What causes Morton's neuroma?

The exact cause of Morton's neuroma is not known, but the choice of footwear seems to be a factor. Wearing high heels (shoes with heels more than 2 inches high) can put extra pressure on the balls of the feet. Wearing tight-fitting narrow or pointed-toed shoes may squeeze the toes together or limit their movement. For that reason, women are about 8 to 10 times more likely to develop a Morton’s neuroma compared with men.

What are the symptoms of Morton's neuroma?

  • A sharp or stinging pain between the toes when standing or walking.
  • Pain in the forefoot between the toes.
  • Swelling between the toes.
  • Tingling ("pins and needles") and numbness.
  • Feeling like there is a "bunched-up sock" or a pebble or marble under the ball of the foot.