If you look at health from nails, the key lies in the color and shape of nails. Healthy nails should be smooth and flat, with no vertical and horizontal grooves on the nail surface, no interference spots on the nail, symmetrical nails, no deviation, no depression or upturned ends. As far as normal nails are concerned, although there are many kinds, there are not exactly the same nails. Generally speaking, healthy nails can be divided into: ordinary nails, big nails, small nails, long nails, short nails, wide nails, narrow nails and so on.