context: Your nails can tell you much more than whether you need a manicure. They're packed with details about your health. They can show if you have an infection, a serious disease, or even how well you're eating. To figure out what your nails might have to say, answer these questions. If you're concerned, ask your doctor, as you'll need more than a glance at your hands to know if there's a problem. 1. Do they look pale or white? This could mean you have a low red blood cell count. White nails also can signal liver disease, diabetes, an overactive thyroid, heart failure, or a lack of nutrients in your diet. If your nails are mostly white with a narrow pink band at the tip, you have a condition called Terry's nails. It can result from aging, but it can also herald diabetes or kidney, liver, or heart disease. 2. Are they yellow? Nails that are thick, slow-growing, and yellow often point to lung diseases like emphysema or chronic bronchitis. Fluid in your lungs and hands also can lead to yellow nail syndrome. So can Raynaud's phenomenon, which is caused by poor circulation to the fingers, toes, and nose. Yellow nails can even be a symptom of sinusitis, thyroid problems, and rheumatoid arthritis. Only your doctor can tell you what they mean. 3. Are your nail beds red? Talk to your doctor. She'll probably want to examine your heart. 4. Do they look a bit blue or purple (without any nail polish)? Your doctor may call this cyanosis, which is a medical word for that skin that looks that way. You might notice it on other parts of your body, too, such as your lips or even your earlobes. It can happen if your red blood cells aren't carrying enough oxygen. Your doctor will see if your heart, lungs, blood cells, and blood vessels are working right. 5. Do you see thin red or brown lines? They're called splinter hemorrhages. They usually come from trauma to your nails or a fungal infection. They can also be from psoriasis, melanoma, or even an infection in the lining of your heart. 6. Are there lines that go from side to side? These are called Beau's lines. Sometimes they come along with a severe illness or injury. Or they might show up afterward. They're also linked with Raynaud's phenomenon. Most often, they're a sign of stress. 7. Are your nails spoon-shaped? This is when your nails get thin and dip down in the middle, sometimes with raised ridges. It can be a sign of heart disease, trauma, lupus, low thyroid, or a problem with iron -- either too little or too much. 8. Are they pitted or split? Psoriasis often starts in your nails. It can make them split and cause pits on the surface. Other causes include inflammatory arthritis or thyroid disease. 9. Are they clubbed? This can cause the ends of your fingers to bulge. Your nails might curve over them and look like the bottom part of an upside down spoon. They can be a sign of lung or heart problems or even inflammatory bowel disease. 10. Are there dark lines or blobs underneath? A thick black or brown line that runs from the bottom to the tip might be melanoma. Sometimes it shows up as a dark-colored blob. 11. Are the nails loose? Lots of things can cause your nails to separate from the nail bed: Long fingernails (the most common cause) Injury or infection Reactions to nail hardeners or adhesives Chemical overexposure from manicures Medications like tetracycline and naproxen, which create light sensitivity and can cause your nails to become photosensitive and lift away from the nail bed Psoriasis, thyroid disease, or other illness, especially if all of the nails are affected Don't ignore changes in your nails, but don't jump to conclusions either. Nails that aren't smooth or aren't one color can be a sign of many diseases -- or of none. Only your doctor can tell for sure. Look for the usual suspects before you assume a serious problem. Bruises, under-the-nail bleeding, and fungal infections are the main cause for nails to crack, peel, or change color and texture. Though common, fungal infections can be hard to treat. If your symptoms don't go away, see a dermatologist. Nail changes are rarely the first sign of illness. Other symptoms almost always appear before that happens. For instance, emphysema causes breathing problems much earlier than it does clubbed nails. An illness may cause nail changes in some people but not in others. Not everyone with liver disease will develop white nails, for example -- and not everyone with white nails has liver disease.