Fingernail Info

Nails grow at different rates due to age, nutrition, and health factors. Under the best of conditions, a nail grows about .004 inches a day or 1/8 of an inch each month.
It takes about six months for a new nail to grow from cuticle to tip.
The matrix is where the nail forms from; this is what most people call "the moon" of the nail. This "moon" appearance is due to the nail bed being so tightly packed with keratin, that the capillaries (where the blood flows through) is covered by the amount of keratin. The rest of the nail that is actually attached to the skin appears pink due to the capillaries running underneath (the blood running through them gives them the pink color). Nails that extend beyond the tip of the finger are white in color because there is no pigment in the nail to give it color.

Nails start in the nail bed, a flat surface that is under your nails and extends about 10mm beyond where you can see them. When cells at the root of the nail bed grow together to form keratin, a nail is formed. Layers of keratin bind together and the nail slowly grow out from the root of the nail bed towards the end of your finger. Nails grow very slowly. The nails you see now won't be fully replaced by entirely new nails until 6 months or more from now.

White spots on the nails are very common and usually recur. These small, semi-circular spots result from injury to the base (matrix) of the nail, where nail cells are produced or imperfections when the nail is formed. As the nail grows these blemishes are pushed outward. Frequently the culprit of these spots is careless manicuring. These spots are not cause for concern and will eventually grow out.

Another leading cause of these white specs is a diet that is deficient in zinc. You could try taking a zinc supplement and see if this clears up the problem.

The nails are flattened, elastic sturctures of a horny texture (mainly protein) that appear in the uterus during the third month of human development.  
They are found on the distal (further out on the limb and opposite of proximal which would be closer in or toward the midline of the body) parts of the dorsal (back side rather than front side) surfaces of fingers and toes. 

The proximal part of the nail, called the ROOT, is implanted into a groove in the skin; the exposed part of the nail is called the BODY of the nail; the distal end forms the FREE BORDER under which you clean when you scrape the dirt from under your nails with a sharp object, and a little proximal to the free border, the skin is attached to the under surface of the nail body forming the HYPONYCHIUM. 

If you have ever had a splinter of wood under you nail it went into this hyponychium layer and will hurt intensely, a very rich nerve supply in this area! 

The root of the nail is overlapped by a fold of skin, the NAIL FOLD, the stratum corneum (cornified = dead; stratum = layer) of which is prolonged distally as a thin cuticular fold, the EPONYCHIUM (cuticle). 
This eponychium covers completely or partially the white opaque crescentic part of the nail called the LUNULE. 

If you look at your own nails you will probably see that some of them show the lunule and some don't; more on the thumb and getting successively less as you go toward the little finger.  If they don't show, just push back the cuticle and you will see them. 
The greater part of each collateral border (sides or edges) of the nail is overlapped by a fold of skin, termed the NAIL WALL, which forms due to the fact the the nail grows much more slowly than the epidermis (skin) and thus the nail wall is formed by the faster-growing skin bulging up over the nail body. 

If you clip the edge of your nail toward the nail wall, but don't clip it all the way off, and then pull it off you may experience another form of pain, not so sharp as the splinter type above. 
What you have done is pull some of the living skin off of the nail wall where it joins the hyponychium and lamen say "I have pulled the nail into the quick".  Of course this word quick is an old English word meaning alive, thus pain. 

Finally, the germinative (growing) zone of the nail bed consists functionally of two parts.  The part beneath the root of the nail and the lunule, called the GERMINAL MATRIX, is thicker and actively  proliferative (dividing), and is concerned with the growth of the nail, the epidermal cells being gradually converted into the nail substance.  On the other hand, the part beneath the rest of the nail, called the STERILE MATRIX, is thinner and is not concerned with nail growth but provides a surface over which the growing nail glides. 

All growth of the nail therefore occurs at its root; the nail increases in thickness from its root to the distal edge of the lunule and the remainder is of uniform thickness.
Therefore, when you happen to miss when using a hammer to drive a nail into a piece of wood and instead hit your thumbnail for example, if you don't damage the germinal matrix you will get a new nail even though the old one might fall off if you hit it hard enough (Ouch!).  The average finger nail grows about 0.5 mm per week with faster growth in the summer than the winter and fingernails grow about 4 times faster than toenails. Whether your fingernails are long or short, strong or weak, they are still made out of the same thing.
Our fingernails are basically made up of a hard, curved plate of keratin.
Keratin is a protein that is also a main ingredient of hair and skin. At the base of a nail is what is called the matrix.
The matrix is where the nail forms from; this is what most people call 'the moon' of the nail. This 'moon' appearance is due to the nail bed being so tightly packed with keratin, that the capillaries (where the blood flows through) is masked by the amount of keratin.
The rest of the nail that is actually attached to the skin appears pink due to the capillaries running underneath (the blood running through them gives them the pink colour). And of course if you are lucky enough to have longish nails, then the ends (called the free edge of the nail) are usually white in colour, as there is no pigment in the nail to give it colour.

Keep them moisturised

We use our nails all the time, but it's when they are in water, that they get the most damage. This is due to a specific type of cell in the nail bed of keratin which acts like an adhesive, holding the keratin closely together to give the nail it's hardness.
If the nail receives repetitive soaking in water, or contact with soaps, dishwashing detergents, and household cleaners etc. it will damage these adhesive cells. So in order to combat this problem use a good moisturiser - one that absorbs really well such as, Nail Doctors - Cuticle Therapy Oil.
Rub it in as often as you can, especially when you come into contact with water and other abrasive products. If you already suffer from brittle nails, this is a must.
What you want to achieve is a seal on the surface, and on the ends of your nails, along with soft, but firm cuticles. This will also prevent dehydration of the skin on your hands, and lessen the chances of dry, cracking nails, along with dry nail beds.

Things that cause cracks & splits

Doing normal things with your nails such as picking things up, drumming them whilst thinking, scratching your itches cause cracks and splits.
There are other things that cause slight trauma to the nails, and these do build up and cause nail damage.

Picking at your nails. This obviously weakens the nails, as it tends to crack or peel the top layer off the free end of the nail.
Biting your nails. couldn't be a more damaging habit, so if you are a nail-biter you are already aware that this habit is destroying your nails.
Picking off nail polish. This is not good for your nails; it will only weaken the outer layer of the nail and peel or split the free nail.

How to improve your nails

Cut your nails after bathing. If your nails are dry and brittle, cutting them when you nails are dry can cause further cracking. So when it's time for a cut, do it when your nails are soft from bathing.

Always have an emery board handy. This is so any potential cracks can be smoothed out, preventing further damage to the nail, and reducing snapping.

If you have fragile nails, the best thing to do is to keep them short.
This reduces damage, as the longer your nails are, the more they stick out and the more they are at risk of cracking and splitting.

Don't push your cuticles back, they are there to protect your nails for a reason, pushing them back can impair the health of your nails. It can also leave the base of the nail open to a potential infection.

Reduce the amount of nail polish remover used. If there is a chip, touch it up with more nail polish, rather than removing it from the whole nail. Try to keep the use of using nail polish remover down to once a week, as it is really bad for your nails, causing them to dry and potentially split.

Keep your nails curved at the top if you like, but don't cut the edges into a curve. Squaring them at the corners, this will help to provide strength, plus reduce the chances of an ingrown nail.

Your nails can reflect the state of your health.
Light trauma such as piano playing or typing on a computer keyboard can actually stimulate the growth of your nails.

You may not realize it, but your fingernails reveal a lot about your general health. Take a look. Are your nails strong and healthy looking? Or do you see ridges or areas of unusual color or shape?
Many less-than-desirable nail conditions can be avoided through proper care, but some actually indicate an illness that requires attention.

Whether you see your nails as decorative or functional, here's what you need to know to keep them in tiptop shape.

Your nails grow from the area under your cuticle (matrix).
As new cells grow, older cells become hard and compacted and are eventually pushed out toward your fingertips.
Nails grow at an average of one-tenth of an inch a month.
The nails grow faster on your dominant hand, and they grow more in summer than in winter.
Nails are also permeable, which means they let in liquids that come in contact with them.

Proper nail care

To keep your nails healthy and looking their best, treat them gently and moisturize them regularly.

Protect your nails. Wear cotton-lined rubber gloves when using soap and water for prolonged periods or when using harsh chemicals. Gloves help protect your nails when washing dishes, for example.

Avoid abusing your nails. Don't use them as tools to pick, poke or pry things.

Don't bite your nails or pick at your cuticles. These types of habits can damage the nail bed.
Even a minor cut alongside your nail can allow bacteria or fungi to enter and cause an infection (paronychia).
Because your nails grow slowly, an injured nail retains signs of an injury for several months.

Moisturize your nails frequently. When you're moisturizing your hands, rub the lotion into your nails as well.

If you rely on manicures to make your nails look good, keep a few things in mind. Don't have your cuticle removed — it can lead to nail infection.

Also, check to be sure that your nail technician properly sterilizes all tools used during your manicure.
Using unsterilized tools may transmit viral infections, such as hepatitis B or warts or possibly even AIDS!.

Weak fingernails can be a challenge to toughen up. If you have weak fingernails, the following tips can help you protect them, making your nails less likely to split or break.

Keep your nails short, square-shaped and slightly rounded on top.

Trim brittle nails after a bath or a 15-minute hand-soak in bath oil. Then apply a moisturizer.

Apply a moisturizer each time you wash your hands. If your nails are brittle, moisturize your nails and cuticles at bedtime and cover them with cotton gloves.

Apply a nail hardener, but avoid products containing toluene sulfonamide or formaldehyde. These chemicals can cause redness or irritate the skin.

Don't use nail polish unnessesarily. Instead, touch up the polish. When you do need a remover, avoid those that use acetone, which dries nails.

Repair splits or tears with nail glue or clear polish.

Avoid dietary changes that supposedly strengthen nails. They won't work. Unless you're deficient in protein — rare among people in the Western World — adding protein to your diet won't strengthen your nails. Similarly, soaking your nails in gelatin won't help, either.

The fingernail is an important structure made of keratin that has 2 purposes.
The fingernail acts as a protective plate and enhances sensation of the fingertip.

The protection function of the fingernail is commonly known, but the sensation function is equally important.
The fingertip has many nerve endings in it allowing us to receive volumes of information about objects we touch.
The nail acts as a counterforce to the fingertip providing even more sensory input when an object is touched.

Nail Growth

Nails grow all the time, but their rate of growth slows down with age and poor circulation. Fingernails grow faster than toenails at a rate of 3mm per month.
It takes 5-6 months for a nail to grow from the root to the free edge.
Toenails grow about 1 mm per month and take 12-18 months to be completely replaced.