Leukonychia striata, transverse leukonychia, or Mees lines are a whitening or discoloration of the nail in bands or "stria" that run parallel the lunula (nail base). This is commonly caused by physical injury or disruption of the nail matrix. Common examples include excessive biting or tapping of the nails, trauma or injury from accidents involving doors or windows, and extensive use of manicure.
Nails that turn completely white, for example, can indicate liver disease, but by the time this happens, you probably would have other symptoms. Incidentally, in addition to the myth that white spots in fingernails are a sign of calcium deficiency, you may also have heard that they indicate a zinc deficiency.
Poisoning and medication that can lead to white areas on or under the nails include:
Thick skin under the toenails, often caused by a fungal condition known as onychomycosis, can make the toenails themselves appear thicker than normal and even take on a yellow or brown discoloration. Onychomycosis can cause the skin to thicken along the outer edge of the nail and directly underneath, according to Columbia University 1 .
3)White part of nail: The white part of the toenail is a normal portion of your tissue called the lunula. This is a normal portion of anatomy where the nail starts to grow. At the root of this is the nail germinal matrix. 4)White under the nails: White under the toenails and nails is …