Nails Can Speak Your Health

Good looking nails look nice in the fingers and attribute sexy look to hand. Nails can speak about diseases one is suffering from. Books on palmistry often describe diseases that one might be suffering from, depending on the character of nails. I have gone through such books in my adolescent days out of curiosity to predict the luck of people.
Nails can be studied basing on the shape, size, texture, color and strength etc..In disease states shape can be like

1. spoon
2. irregular towards ends
3. clubbed
4. ribbed

.Texture can be

1. bright
2. pale looking

. Color can be

1. Bluish
2. dark or black
3. yellow
4. small bleeding spots under nail

.It may be brittle.
Spoon shaped nail called Koilonychia, is the hallmark of anemia especially due vitamin B12 defiency. Nails also look pale in this condition. 
Irregular ends of nail indicate tooth bite, which in turn indicate personality disorders like a feeling of insecurity. 
Clubbing of fingers seen in

1. cyanotic heart diseases
2. pus forming lung diseases
3. chronic bronchitis
4. infective heart diseases
5. tuberculosis of lungs
6. cancer of lungs
7. liver diseases like cirrhosis and hepatoma
8. intestinal diseases like crohns disease

. Bluish coloration seen in

1. congenital cyanotic heart diseases
2. respiratory distress syndromes
3. heart and lungs failure

Yellow nails indicate jaundice from various causes. 
A dark nail may be due to fungal infection. 
Yellowish brittle nails are seen in psoriasis.
Splinter hemorrhages can be seen in cirrhosis of liver.
Brittle nails as such can be seen in calcium deficiency states. Ribbed nails are seen in malnutrition states. 
These are some of clues from nail to reach or suspect a disease. There can be many more, I might be missing.
Now, I say that our forefathers, actually have keenly observed the nails in different diseases and narrated in the books on palmistry, to predict fate of people. And, I hope those were scientific.