You don’t like much about your fingernails unless you are to pick your favorite nail polish color. But at some point or another, we’ve probably all seen some strange things happening to our nails every day. But what do changes of our finger nails really mean? We asked top dermatologists to explain eight weird things that can happen and what they signal about your health.

People tend to think white spots are due to a systemic cause, like calcium deficiency. In reality, there are several causes for the pesky dots, but few of them are problematic and none point to a deficiency.  The most common cause is trauma to the nail or to the end of your finger right before your nail. The matrix, a layer of cells at the base of your fingernail, is in charge of building the nail. If it’s damaged, the spots can pop up. Or maybe a prolonged polish wear, which can partially break down the surface of the nail plate. If you notice white spots that are powdery in consistency? An infection with a fungus could be to blame.

Yellow nails could be a stain from polish. So think about how many manicures you have had recently. But this change in color could also signal diseases like diabetes, which need to be treated by prescription or insulin. Yellow Nail Syndrome, where the nail thickens, turns yellow, and growth slows, is often a sign of a respiratory disease like bronchitis too.

If your nails seem softer and the tips of your fingers appear larger or bulging, you might have something more serious on your hands. An increase in the tissue around the ends of your fingers, right where the nail curves, can indicate lung disease, it is sometimes caused by low oxygen in the blood. But clubbing nails are also associated with inflammatory bowel disease, cardiovascular disease, AIDS, and liver disease. And Adigun notes that chronic respiratory disease or cardiothoracic disease could also be contributors. 

Overdoing it with nail polish remover can cause this, but so can frequent dishwashing, sans gloves, or swimming.  If you suffer from hypothyroidism, when your thyroid is working too slow, it’s possible to see brittleness, too. The weather could also be to blame. Fall and wintry weather and drying indoor heating systems can bring about more dry air. The good news is that the solution may be as simple as adding moisture back in.

Chefs, bartenders, or health-care workers may notice their fingernails separate from their nail bed. It seems scary, but often, it’s due to irritation from excessive water exposure. A too-aggressive manicure, nail hardeners, or glues could also cause the damage. Notice changes in nail color to opaque white, green, or yellow? That could point to everything from a thyroid disease or psoriasis to injury and infection. See your doc if you think something more serious could be the cause and try to keep your hands dry whenever possible.

Nails curving up? Time to have some bloodwork done. A very thin nail which becomes concave in shape is usually a sign of iron deficiency or anemia. If you’re deficient, a supplement will likely fix the problem. But ask your doctor about other issues that could be involved, too. Liver disease, heart disease, and hypothyroidism are also linked to spoon nails.

Those thin lines that run vertically up your nail are likely totally normal. Vertical nail ridges are sometimes from aging. Think about them like the wrinkles of your nails, she says. Your best bet is keeping your nails and cuticles moisturized.

Little indents that look like they were made from a mini ice pick occur in up to 50 percent of people with the psoriasis (a skin condition). It can also happen to people with alopecia areata, an autoimmune disease in which you lose patches of hair. Creams with vitamin A and vitamin D can help, and in some cases, steroid creams can be used.