Unless you live on Key West, it's likely that your hands are the only skin on your body that remains exposed all year long. It's important to include them in your beauty routine. Let's start with the nails.
Nail Composition and Growth
Along with the skin and hair, they make up the body's integumentary system—the organ system that protects the rest of your body from damage. The fingernails are composed of a tight mesh of structural proteins called keratins. A cell matrix beneath the base of the nail generates epithelial cells that become hard and platelike, or keratinized, as the nail grows. The part of the nail you can see is called the nail body. The milky-white crescent of tissue at the base of the nail body, the lunula, indicates new nail growth. This growth occurs at the rate of 0.5 mm per month (1 mm is about the thickness of a dime). The cuticle protects against infection of the tissues that surround the nail. Such an infection is called paronychia and is caused by bacteria or fungus.
The nail bed is the pinkish area (in light-skinned people) or dark area (in people of color) beneath the fingernail. Trauma to the nail can cause it to detach from the nail bed. This condition, called onycholysis, is generally not worrisome but sometimes indicates an overactive thyroid gland.
As we age, the nails become flatter and more brittle. The lunula becomes less noticeable. The blood supply to the vessel-rich nail bed decreases. Nail growth slows, making it more difficult to treat fungal infection, or onychomycosis. Such infections may become more frequent as general health declines.
Potential Nail Problems
Changes in the appearance of the fingernails are often a good indicator of our general health. Vertical ridges and white spots are normal. Grooves or depressions across the nail have many causes, some of which are of serious concern, so this condition should be evaluated by a doctor. Tiny pits in the nails can be a sign of nutritional deficiency. Clubbing of the nails—that is, a broadened fingertip with a rounded nail—suggests lung, heart, liver, or inflammatory bowel disease. Bluish nails indicate a lack of oxygen in the blood, caused by conditions such as chronic obstructive lung disease, and should be investigated by a physician right away. Dark red or brown vertical lines are known as splinter hemorrhages and may be a sign of infection of the heart valves. This condition should also be investigated.
Nail splitting occurs when the layers of the nail separate horizontally at the edge of the nail. This condition is common among people who wash their hands frequently, such as cooks and nurses. Nutritional factors and medications can also contribute to brittle nails.
To keep your nails healthy, cut them straight across and don't bite them! If you use nail polish and nail polish remover, avoid dibutyl phthalate (DBP), formaldehyde, and toluene. Although all of these chemicals are legal and considered safe up to certain exposure limits, they can all be hazardous under certain conditions. According to the Occupational Safety and Health Administration (OSHA), DBP has caused neurological toxicity in workers exposed to high concentrations of it over extended periods of time. It may also cause menstrual irregularities and complications of pregnancy. Toluene is harmful if inhaled or absorbed through the skin, or if it comes into contact with the eyes. OSHA reports that formaldehyde can be "reasonably anticipated to be a human carcinogen."
Hand rejuvenation is becoming a popular option for those who can afford more than a weekly manicure. A new use for dermal fillers is to give a fleshier look to bony hands. Wrinkles and age spots on the hands can be removed with dermabrasion, laser treatments, or prescription-fade creams. Wormlike veins can be injected with a detergent-like chemical that causes the veins to collapse. We have to wonder, though: Is hand rejuvenation going too far? Like our faces, our hands are unique and recognizable to those who know and love us—wormy veins and all.