• When we look at our nails, we see a white portion at the base, what is this?
• According to the American Academy of Dermatology, there are three parts to a finger nail.
• The small, white colour, half-moon shaped feature that can be seen at the bottom of the nail, especially in the case of thumb, is called lunula.
• The lunula is present under the skin and is part of the matrix which can be seen through the transparent nail plate proximal to the pink nail bed.
• Alterations in the morphologic features or colour (or both) of the lunula can be an indication of either a cutaneous or a systemic disorder.
• For instance, the white lunula turns blue in the case of Wilson’s disease.
• It may become red in cardiac failure or due to carbon monoxide poisoning.
• Generally, lunula becomes smaller or absent in old age.

Source: The Hindu