What are the white semi-circles on a person’s nails?


I noticed I have quite big ones but my partner has practically none.

In: Biology


I’m no expert, but according to my own research for curiosity purposes:

There are a lot of complicated names for a lot of different bits of the nail structure. The white semi-circle you’re talking about is called the **lunula**, and it’s actually just the visible portion of a larger structure called the **matrix** under the root end of your nails, underneath your skin. The matrix is the tissue that actually builds new nail cells, which is what causes your nails to get longer.

The shape of the matrix – and therefore the shape of nail that it grows – is mostly determined by stuff like bone structure. Some people just have more of their nail matrix visible i.e. a larger lunula.

Source: wikipedia, healthline.com, [knowyourbody.net](https://knowyourbody.net), etc