A neuroma is a noncancerous (benign) growth of nerve tissue that can develop in various parts of your body. Morton's neuroma occurs in a nerve in your foot, often between your third and fourth toes.
The condition isn't a true tumor, but instead involves a thickening of the tissue around one of the nerves leading to your toes. Morton's neuroma causes a sharp, burning pain in the ball of your foot. Your toes also may sting, burn or feel numb if you have Morton's neuroma.
Typically, there's no outward sign of this condition, such as a lump. Instead, you may experience the following symptoms:
- A burning pain in the ball of your foot that may radiate into your toes
- Tingling or numbness in your toes
At first, the pain may worsen when you wear tight or narrow shoes or engage in activities that place pressure on your foot. Over time, though, symptoms may last for days or weeks.
Doctors don't understand exactly what causes Morton's neuroma. The condition seems to occur in response to irritation, pressure or injury to one of the digital nerves that lead to your toes. The growth of thickened nerve tissue (neuroma) is part of your body's response to the irritation or injury. Factors that appear to contribute to Morton's neuroma include:
- Wearing high-heeled shoes or shoes that are tight or ill-fitting, including those that box in your feet and place pressure on your toes
- High-impact athletic activities, such as jogging, that may subject your feet to repetitive trauma
- Injury to your foot
In some cases, Morton's neuroma may result from abnormal movement of your foot, caused by bunions, hammertoes, flatfeet or excessive flexibility. In some cases, there's no clear cause of pressure or irritation.
Because there's typically no outward sign of Morton's neuroma, your doctor will try to find a palpable, tender mass. There may also be a feeling of "clicking" between the bones of your foot. X-rays of your foot are usually ordered to rule out other foot problems.
Treatment depends on the severity of your symptoms. Conservative approaches are always attempted first. This may include resting your foot, changing to better-fitting shoes and taking over-the-counter medications to reduce inflammation and relieve pain. If your pain is severe or persistent, or conservative approaches aren't working, you may need:
- Corticosteroid injections - Steroids are medications that reduce inflammation. An injection of a corticosteroid medication in the area of the neuroma may reduce pain. However, overuse of injected steroids can lead to a number of side effects, including weight gain and high blood pressure, so people usually receive only a limited number of injections.
- Surgery - Surgical removal of the growth may be necessary if other treatments fail to provide pain relief. Although surgery is usually highly successful, doctors often turn to surgery as a last resort, because the procedure removes both the neuroma and the nerve, which can leave permanent numbness in the affected toes.