If you do a lot of housework, it's exposure to detergents and cleansers; if you're a janitor, strong cleaning fluids; a bartender, citrus fruits; and so on. If you can't stay away from these substances, wear gloves whenever possible. Otherwise, you risk brittle nails and even nail separation or infection, which could lead to nail deformity or even loss of the nail. Also, the shorter your nails, the less the risk of damaging them.
Vinyl gloves. Wear vinyl gloves for wet work. Exposing your hands to moisture too often, or getting your hands in harsh detergents or chemicals, can cause brittle nails. Wearing vinyl gloves, not latex or rubber, keeps your hands dry and safe from abrasive materials. To repel moisture even more, try sprinkling a little baby powder in your gloves, or wear a pair of cotton inserts under the gloves.
Cotton gloves. For dry work, wear cotton gloves. You'll help protect nails from damage or possible injury.
Also, don't use your nail in place of a screwdriver, a scraper, or other tool. Try not to hit it with a hammer or slam it in drawers. You get the idea. Such actions can injure your nails, opening the door to infection, stopping nail growth, or causing bruises. See your doctor as soon as possible if a nail turns black and blue; if your physician isn't available, go to an emergency room. The pressure should be relieved on the blood vessel that's been injured underneath the nail.