There are at least 45 different possible causes for white fingernails according to RightDiagnosis. These causes range from having white nails at birth, known as congenital white nails, to the more serious cause of arsenic poisoning.
The color, shape and texture of a person's nails can be very informative to physicians, according to WebMD. Some people are simply born with white nails, and in those cases, there is no cause for concern, according to MedicineNet.com. However some people develop white nails later in life, which may indicate a significant issue or health problem.
There is a wide range of possible reasons for fingernails to turn white, including iron deficient anemia, malnutrition, yeast infection, kidney disease, congestive heart failure and diabetes mellitus. If the nails are white and darker at the tip, it may indicate a condition referred to as Terry's nail, which is often indicative of serious liver problems. Because there are so many medical conditions that can cause a person's nails to turn white, RightDiagnosis suggests that those who have any concerns discuss the change in the color of their nails with their physician. It is especially advisable to do so if white nails occur with any other symptoms.