We humans love our nails. We spend nearly 8 billion dollars a year on those hard dead shell like materials on the tips of our fingers and toes. While adorning them with polish, varnish and even art may imply “cosmetic” and “superficial”, as it turns out, their condition, for better or worse, is a function of the entire body, and if you’re observant you can tell a lot about overall physical health by looking at the nails.
Technically speaking, nails are an extension of the skin. They’re a modified version of the epidermis,
the top layer that composes about 10 percent of the body’s largest organ. Although it may look like one uniform structure, in reality, the nail (like the skin) is composed of numerous layers lying atop of each other. In fact, the average fingernail is composed of 25 of these ultra-thin slices that fuse into a firm, slightly elastic form by the action of microscopic threads called keratin. This is what gives them remarkable resilience and horse-hoof like strength. Keratin is a hard, flexible protein substance that is a common feature of hooves, horns, antlers, as well as the outer sheath that coats human hair. In addition to keratin, nails contain lots of minerals too, including: Iron, Carbon, Magnesium, Selenium, Silica, Calcium, Potassium, Phosphorus, Sulfur and Oxygen, all of which contribute to their characteristic qualities. Interestingly the nail appendage (technically called the “nail organ”) also contains small amounts of the well-known cosmetic ingredient called glycolic acid, which acts to trap water and assure hydration.
Because of their rapid growth (healthy fingernails grow up to 4mm a month) the nails are an accurate portal into the inside of the body. While the eyes may be the window to the soul, the nails can be thought of as windows to your biochemistry. There’s a lot of information a good health care professional can glean from their appearance.