Location: Nails are essentially hard skin cells located at the end of every finger and toe. They’re made mostly of keratin, a protein found in the skin and hair. Nails are made when living cells are produced in the lunula, the white half moon area visible at the base of the nail. As new cells are produced, the old cells are pushed forward, where they harden to make a visible nail. Nails grow at varied rates — faster in summer than in winter, faster in men than in women, and faster on the dominant hand. Fingernails grow about 2 to 3 millimeters a month, while toenails creep along at 1 millimeter per month.

Function: Finger- and toenails may not have any health function, other than to protect the ends of the fingers. They make many tasks involving the fingers easier, and of course, are unmatched when it comes to scratching an itch.

Potential problems: Trauma to the finger, like getting it caught in a door, can lead to white spots or red lines resembling splinters. If you experience such discolorations and can’t remember injuring the finger, you may want to check with a doctor. Some medical conditions can also cause those to appear. Ingrown toenails occur when the nail curves downward into the skin. The big toe is particularly vulnerable. But avoid trying to dig out the nail on your own; it can lead to infection and more problems.

About 12 percent of Americans will have fungal infections, again mostly affecting the toes. Topical anti-fungals may help, but many will require an oral medication to resolve the issue.

Avoid biting your nails; it’s a great way to ingest infectious material.

— Markian Hawryluk