What cause fingernails to be striated?

What cause fingernails to be striated?
Many causes.Fungal infection,insufficiency of Calcium,Chitin or loss of salts close to calcium,phosphorous etc can lead to such a state.Fungal infection cause Onychomysis also.In some cases lack of blood supply also results within this.
They are a specialized form of hair.
poor contemplation, and not proper filing it deserves ..
surrounded by other words ... STOP SCARTCHING YOUR BUTT!!
Nail shapes: Nails that tend to curl under at the tips can signify respiratory or heart problems, while nail that are raised at the bottom can also signal respiratory trouble. Square, wide nail can be a result of a hormonal disorder while flat, thin nail can be from insufficient vitamin B12.
The texture of fingernails can tell as much give or take a few a persons standard health as the color can. Below are some adjectives texture abnormalities and what they can possibly indicate.
Nail texture: Vertical ridges that appear on the nail can indicate disorders as simple as iron lesser amount, poor absorption of vitamins and nutrients, overall poor robustness or they could indicate something as serious as kidney trouble. (So, you see why consulting your physician is so important.) These vertical ridges, as all right as bumpy nails, can also suggest that one is prone to developing arthritis. Ridges running horizontally across the pin can indicate physical or mental stress.
Nutrition plays an extremely important role within every function of our bodies, right down to the tips of our fingers and toes, literally. As well as signs of other possible disorders, nail can let us know how we make a payment up when it comes to getting all of our required nutrients.