Fingernails are made from dead cells bound together as a tough plate. So any good healthy diet will look after your nails, because it will keep your cell production up. Include leafy green vegetables, eggs and milk in your diet to make sure you get all those cell producing nutrients.

Note: turns out there are more things that can cause each of the symptoms below than I have time to write up. So I have only put in the most likely candidates - if you have any of these problems - go see a doctor and sort them out for good!

Do you have white dots in your nails?

Note, these white dots appear at the cuticle end of the nail and grow out. If white dots appears at the tip of the nail it may be fungi.

Do you have corrugated nails?

If both hand and foot nails are growing in a horizontal wave pattern, resulting in corrugations (ridges) on the nail surface, you may be lacking in calcium. Go and see your doctor, as this can be an indication that your body is not taking up calcium, as it should be doing, also it can indicate heart disease.

Or how about some Beau's lines?

Are your nails spoon shaped and pale?

Do your nails flake?

Do they look like the nail has split into thin sheets? This can be a result of poor diet, the side effect of some medication, or from putting your hands into water a lot. Unfortunately wearing rubber or latex gloves can also cause this problem.

Or you can use a nail stone to waterproof your nails. To do this first cut the nail down until the flaking edges have all been removed, then use the stone to file the edges smooth with. The idea is that the stone heats and seals the edges of the nail so that water can not enter the porous, exposed edge and cause the flaking.

Be careful about applying binding glue or other ointments to the nail bed, they can effect the growing nail, by suffocating it.

If you must rub in growth promoting moisturisers (and I think their effects are questionable) then rub them in at the base of the nail, where new nail is grown. This keeps the moisturiser away from the edges and puts it where it will do the most good. You can not moisturise the tips of your nails - they can not be improved, they have already grown.

Fungi

Is there a dark stain coming from the tips of your nail towards the hand? Or are the nail stains yellowish and the edges crumbly? It is likely that the layers of your nail have split, water has entered the area between them and a fungus has grown.

What to do! Act immediately as the longer you leave it the harder it will be to fix. Cut your nails (might as well do all of them at once, even if the others don't look like they have any - yet!).

No need to cut them to the quick, but fairly close to the finger will help. Now, run to the nearest chemist and ask for their help in choosing the latest and most effective nail fungi treatment.

Also, if you wear false nails, keep an eye out for dark stains on the nail bed. If you see any that you believe to be fungi, have them removed right away, as fungi on the nail bed can be pretty devastating!

Onycholysis (loose nails)

Pitting

Splinter Haemorrhages

They look like red splinters under your nail and are produced by small blood vessels bursting. They are caused by trauma to the nails (most common reason!), or represent undue blood clotting caused by Endocarditis - inflammation of the heart disease. If they turn up and you can not remember hitting your finger at any point - go see a doctor.

Strengthening Weak Nails

Apply a thin coat of Nail Strengthener. Be sure it is a 'thin' coat, because you'll be applying it daily. You don't want it to build up too much or you'll end up with gluggy thickenings at the tip of your nails.

Also a good all round vitamin supplement will prevent any of the defects that deficiencies can produce. Healthy, well fed nails are stronger nails.

Nail Biting.

Hypnosis and acupuncture have been known to work. Why is a question for another web site .

Therapy looks at the reasons why someone is feeling unsettled and needs the comfort gesture of biting their nails. They then work on building your self-esteem etc.

You can buy a wide variety of liquids to put on your nails that taste bad.

Keep nails cut short so the edges don't tempt you to bite them. Covering the ends of your fingers in band-aides stops you getting at them, so will wearing cotton gloves.

Alternatively you could try applying stick on nail tips until your own grow out. The hard tips will allow your own nail to grow enough that you will begin to like them and start to treat them with respect and not despair that they will never lengthen.

Living with long nails.

Having long nails means a certain amount of difficulty is going to have to be faced and over come. And at some point practicality will have to be placed above your love of glittering green dragon claws. For instance, very long nails and contact lenses should not mix.

Having trouble hitting tiny keypad buttons i.e. on mobile phones etc? Use the end of a pencil/chopstick to press the buttons for you.

Carry a tiny screwdriver set so you are not tempted to use your nail tip as a tool.

Open bottles using the area between the side of your pointer finger and your thumb, this grip avoids skewering the palm of your hand with your own nails.

Use a split drinking straw to pick up any tiny objects with. Or lick a finger and press down on the item - it will come up, but depending on material and weight will soon drop off again.