Hammer toe is bending of one or both joints of the second, third, fourth, or fifth (little) toes. This abnormal bending can put pressure on the toe when wearing shoes, causing callosities to develop. Hammertoes usually start out as mild deformities and get progressively worse over time. In the earlier stages, hammertoes are flexible and the symptoms can often be managed with noninvasive measures. But if left untreated, hammertoes can become more rigid and surgery is needed to correct the deformity.