If you know what you're looking for, the current state of your fingernails can tell you a lot about the current state of your health in general. Here are five things about your nails that can tell you how healthy you are.
#1.) The White Part Under Each Nail. At the base of your nails, there should be a little white showing. If there is, it's a sign your thyroid is healthy. But if most of your fingers DON'T have white showing at the base, your thyroid might be weak, which can lead to depression, mood swings, and thinning hair.
#2.) White Spots Under Your Nails. It's a sign you have a zinc deficiency, which can cause diarrhea, impotence, hair loss, loss of appetite, and also weaken your immune system. You can get zinc from oysters, sesame seeds, dark chocolate, and peanuts.
#3.) Ridges. Your nails should be relatively smooth on top, but If they're made up of ridges and you can see a bunch of parallel vertical lines, it's a sign you're not getting enough iron. If the ridges run horizontally, it's a sign you're not getting enough vitamin A or vitamin C. You can get vitamin A in dark green vegetables. And obviously citrus fruit is a good source of vitamin C.
#4.) Black Lines. If there's a thin, black line under your nail, it might just be a "splinter hemorrhage," which is caused by trauma . . . like hitting your finger with a hammer or slamming it in a door. In that case, it'll just grow out within a few months. But it could also be a sign of heart problems or even cancer. So if one shows up and it's not the result of trauma, get it checked out.
#5.) Dark Fingernails. Cigarettes and using too much nail polish can turn your nails yellow. But yellow nails can also be caused by diabetes, lung problems, arthritis, lupus, and liver disease. And not having enough B-12 in your diet can also make your nails darker. B-12 is found in fish, meat, and dairy products.