A neuroma of the foot, (often called Morton's Neuroma) is an abnormal thickening or swelling of the nerve that runs on the bottom of the foot between the 3rd and 4th  metatarsal bones. This thickening or swelling of the nerve is caused by an irritation to the nerve that takes place over a period of time. This irritation is caused by excessive pressure, motion or trauma to the front part of the foot resulting in shooting and burning pains into the toes  (most commonly the 3rd and 4th toes)  or ball of the foot.  

These unpleasant sensations generally occurs while the person is walking with shoes on or standing for a period of time; and may improve or even disappear once the shoes are removed and the painful area is massaged. In more severe cases these discomforts can even radiate up the leg.

The leading cause of neuroma is abnormal function of the foot which improperly causes the metatarsal bones to squeeze or choke the nerve, which cause swelling and inflammation of the nerve to occur. The reason for the abnormal foot motion to start with is typically due to a Morton's Toe.  It is funny but the Morton's Neuroma  is caused by the Morton's Toe .