A neuroma is a thickening of nerve tissue. Morton's neuroma refers to a lump of nerve tissue that forms on the branches of the plantar nerve on the sole of the foot. It is most commonly found in the webspace between the third and fourth toes (metatarsals), but can also occur between the other toes. The nerve most commonly involved is the third interdigital nerve.
Though the term 'neuroma' is used in other contexts to mean tumour, Morton's neuroma is completely benign. For this reason, it is also known as 'Morton's metatarsalgia' .
Morton's neuroma presents as an increasingly painful lump in the ball of the foot, as though a pebble has become stuck in the skin. Irritation of the nerve can cause numbness and tingling through the foot.
Women are more likely to develop Morton's neuroma than men, and it is believed that this is due to footwear. Morton's neuroma can be treated through wearing appropriate foorwear, through analgesic medication, and if necessary through surgery.