Apple #104: Fingernails

(photo from A Sizable Apple blog of health tips)

I was filing down a rough spot in my fingernail and I thought, "I bet there are a few things about fingernails that I don't know." So I checked it out, and I was right. Here are a few fingernail facts:

• Fingernails grow from the white, half-moon shape often visible at the base of the nail. This is called the "growth plate" or "lunula".
  

• As more cells form in the growth plate, the older cells are pushed forward. During this growth process, the cells die and become filled with a hard protein called keratin. It is keratin that makes the nails hard.

• A fingernail grows about 1/10th of an inch per month. It takes 6 to 9 months to grow a nail from cuticle to fingertip.

• Fingernails also have a high sulfur content. This is why, if you accidentally burn your fingernail, say, in the flame of a candle, it stinks something awful.

• Nails are ten times more porous than skin and can become chapped. Chapped nails are more likely to break in response to environmental damage -- that is, when you use your nails to pry something open, or when you catch them on things, or when you do a lot of gardening.

• Infants' fingernails are very thin. Their nails tend to get torn rather than cut.

• As people age, their fingernails get thin. Their toenails, however, get thick.

• Changes in your fingernails may reflect changes in nutrient levels. There are some pretty creepy pictures of fingernails and in some cases, yeah, it's obvious, these people have something really wrong.

• If the pink skin under the nail is spoon-shaped, rather than rounding upwards, or if it is pale rather than pink, you may have low iron levels.

• Yellow or green nails may signal a respiratory condition, or swelling. The discoloration occurs because the growth of new cells has slowed.

• Pitting, or what looks like tiny holes or scratches in the nail surface, is common in people who have psoriasis, a condition that makes scaly patches in the skin.

• When the tips of your fingers enlarge and the nails curve around the tips, almost like claws, this is called clubbing. This signals low oxygen levels in the blood and can be a sign of lung disease. Come to think of it, I've noticed nails like this on older women who are hard-core smokers.

• If the nails have ridges that run side to side, you may have recently had a fever or inflammation. In people who have recently had a heart attack, these depressions can be very deep, so that it looks like they slammed their fingers very hard in a door.
  

• If your nails have ridges that run lengthwise, this is a signal of age and not any particular problem.

• White spots on the nail are commonly said to be because of a zinc deficiency or a lack of calcium. Many doctors & dermatologists say that's a myth. Actually, the white spots are usually the result of some injury, like dropping something heavy on your hand so that it hits the nail just wrong, or catching your hand in the door. It may take several days before the white spot shows up, so most people don't remember the injury and attribute the white spot to that event.

White marks on the nail are called leukonychia. Despite the important-sounding name, most of the time, they're caused by some mild injury and are nothing to worry about.
(Photo from the Gemini Geek)

• Another, less common, possible cause is an allergic reaction to nail polish, polish remover, or nail hardener. If you get lots of manicures and lots of white spots, hold off on the manicures for a while and see if that takes care of the white spots.

• It is also possible that the white spots could be signs of an infection. This is unusual, however. If they get bigger, then it might be time to look into treatment. But probably they'll get smaller and fade away on their own.

• For those of you who want to take extra care of your fingernails:
  

• Don't have the cuticle removed. This makes your skin susceptible to bacteria, and it can also weaken the nail. Plus, it hurts like hell.

• Do rub hand lotion into your nails.

• Some nail polish and polish removers can irritate the skin or dry the nails and actually make them weaker, instead of stronger, which is what people think nail polish can do. Avoid polishes and removers that contain sulfonamide, formaldehyde, or acetone.
  

• Drinking Jell-O or other gelatin products will have no effect on the strength of your nails. While gelatin contains protein, and protein is an essential part of fingernail cells, protein is essential to lots of other cells in your body, too, and the protein you eat gets all mixed into the protein pool, so to speak, and gets used in all kinds of part of your body. Extra protein from gelatin would not "go to" your nails but would get stored as fat.

Sources
MadSci Network, "Are our fingernails made up of stiff hair?"
Ask the Dietician, Fingernails, Hair & Skin
Mayo Clinic, What your fingernails can tell you about your health
CNN.com, sourced from Mayo Clinic.com, Fingernails: keep them healthy and strong
Health Guidance, What Causes White Spots on Fingernails?
Dr. Weil, Worried about White Spots on Fingernails?
WiseGeek, What Causes White Spots on Fingernails?