Originally posted by BabyLover:
scratch ur head la.. kaoz!
wen ni deng yu mei wen.. haiz
from a forum

There are several different factors that would determine the strength or weakness of your nails. The first is genetics; if your parents have thin, weak nails, so will you. The second is your internal health, followed by not wearing gloves whenever having your hand in water, using household cleaning solutions, or if you work with a lot of paper or textiles. All of these things will wick the natural oils and moisture from the nail plate, leaving them weak and prone to breakage.
If your nails have always been like this, chances are that it is genetic. The nail root will produce only a certain amount of cells that make up the nail plate layers. The deepest portion of the root creates the cells that develop into the portion of nail that touches the nail bed. The highest portion of the root (ehich can be seen as the white half-moon at the cuticle) create the cells that develop into the surface of the nail plate. If the Matrix (root) is very short, less cells are produced, therefore, the nail plate will be thinner and weaker.