There is no nail on the pinky toe, and the possible clinical causes include heredity, trauma, and gray nails. 1. Heredity: this situation is relatively rare, part of the population in the birth of the pinky toe area has no nails, the subsequent growth process has not grown again, which is usually related to genetic factors, it is recommended to consider the family hereditary factors. 2. Traumatic injury: some people are missing nails when their bunions are accidentally hit by external forces, such as heavy objects or burns. This condition usually grows back after the injury to the little finger is recovered, and the local area should be kept clean during the recovery period to avoid infection. 3. Gray nails: this refers to the nail lesions caused by the infection of the nail bed of the thumb by the skin fungus, which is related to the fact that the affected people often wear breathable shoes, and have a history of tinea pedis or tinea cruris, etc. The clinical manifestations of this condition include shrinkage, buckling, peeling off, and discoloration of the nails of the thumb. If the missing thumbnail is caused by a disease, it is recommended to go to the hospital to get a clear diagnosis so that targeted treatment can be carried out.