I'm a girl and I work in a nail salon in Manhattan, New York. Today I read an article from the internet so I now am sharing it with you guys:

Other than manicurists, most people don’t spend a lot of time thinking about fingernails. But did you know that they can tell you if you have a disease?

Just for a moment, take a good look at your fingernails. If you have polish on your nails, take it off and give those nails a breather for a while. our nails should be smooth and should have a lighter half circle where the nail starts growing from. That little area is called the “lunula,” Latin for “little moon.” Your skin should overlap the nail where it grows from and it should abut it on the sides. Your fingernails ideally should be kept short, overlapping the skin by about a millimeter.

But fashion often trumps good health decisions, and many women (and a few men) place polish on their nails. While that polish isn’t particularly healthy for your body, we’ll save that discussion for another blog. Importantly, the polish hides an important window into the health of your body.

All sorts of illnesses can make your fingernails look funny. Psoriasis and fungal infections are the most common problems with nails, causing them to grow thick and crack. But it’s those lines that cross the nail, not run with the length of it, that are of real concern. These lines (called Beau’s lines), start at the lunula and grow out with the nail. They can occur with syphilis, diabetes, heart disease, peripheral vascular disease, zinc deficiency, and after high fevers or after chemotherapy. And nails can become spoon-like with iron deficiency anemia, and the ends of the fingers can grow into clubs with lung and heart disease, cirrhosis and thyroid disease. Yellow nails can mean you have certain lung diseases or even AIDS. And the prettiest nails, called “Terry’s nails” can mean you have diabetes, cirrhosis or heart failure. These nails are white or light pink and have a narrow normal pink band near the end of the fingernail.

And there are a lot of other diseases that change your nails. But now that you’re worried, what about those long ridges that so many people get? Relax. They're normal. And the dark bands in African American fingernails? Also normal.

So take a good look at your nails. If they look a little funny, visit your doctor.