The thickness, shape and color of the nails can all point out some health problems. They may be the warning sign of an impending disease. Stains on the nails, color irregularity and the thickness can also indicate some internal issues.
If the shape of your nails is curved outwards and looks like spoon that means that you have some heart disease or your iron levels are high or low.
The healthy nail has a pinkish color with a white shade on the root. Green nail signal bacterial infection while red lines on the nails indicate a heart problem. Blue nails are a sign of lack of oxygen in the blood, and lifeless nails occur due to lack of vitamins. Dark spots on the nails indicate aging, and white nails are a sign of liver problems.