Onychauxis and Onychogryphosis

Onychauxis is a thickening (hypertrophy) of the base of the nail (nail bed). Onychogryphosis is long-standing thickening, in which typically a curved hooked nail (ram's horn nail) occurs.

The thickening of a nail, which is common in older people, may be caused by several factors, including injury (such as that caused by ill-fitting shoes), infection, poor blood supply, diabetes, or inadequate intake of nutrients.

Pressure on an affected nail (even from bedsheets) may produce severe pain. Onychogryphosis may occur at the same time, almost always resulting from damage to the nail bed. In onychogryphosis, the curved hooked nail may injure an adjoining toe.

The nails should be kept trimmed, and injury to nearby toes can be prevented by placing lambswool between the toes. Footwear or stockings that gather at the toes should be avoided.