Diagnosis using the nail bed and hyponychium.

"Nails protect the fingertips and toes. Diseases affecting the nail can cause cosmetic disfigurement and social embarrassment. Physical functioning may be impaired. Disorders of the nail bed may cause pain or create difficulty grasping fine objects. The nail bed is the area beneath the nail plate between the lunula and the hyponychium. Disorders of the nail bed can cause onycholysis, subungual hyperkeratosis, and/or onychogryphosis. Ventral pterygium is less common. Tumors of the nail bed are rare and commonly missed."