Here are some other telltale signs:
- Nail clubbing. Nails normally curve at a slight upward angle from the nail bed. Nails that curve downward could be indicative of lung, cardiovascular, liver or inflammatory bowel disease or HIV infection.
- Spoon nails (koilonychia). This refers to nails that are abnormally thin and flat—or even concave enough to hold a drop of water. The condition is associated with severe iron-deficiency anemia and other systemic illnesses, and commonly results from repeated exposure to chemicals or trauma.
- Horizontal indentations (Beau’s lines). These lines may be a sign of injury to the nail or of peripheral vascular disease, diabetes or zinc deficiency. They can occur as a result of a high fever and in people being treated with chemotherapy.
- White bands (Muehrcke’s nails). This condition is characterized by a pair of horizontal white lines running parallel to the nail base. It can be associated with liver or kidney disease and may also occur because of chemotherapy.
- White nail plates (Terry’s nails). Characterized by white nails with a dark band at the tip, seen on all fingers, Terry’s nails are common in people with liver disease and are also associated with congestive heart failure, diabetes and HIV, though they may also occur as part of normal aging.