What do yellow nails mean...i usually wear nail polish 7 days a week.?

A few things: Theres a rare disorder called yellow nail syndrome, i've never seen a case of it and it is very rare and is usually associated with respiratory symotoms! it could be due to smoking or a nutritional disorder. If you have any other symtoms it would help to establish a firmer diagnosis. However, my best guess is that you like to wear red nail polish, which is notorious for leaving nails yellow!

Yellow nails: Fingernails that are yellow can be an indication of a medical disorder in some cases. These include liver disease, lung disease, diabetes, kidney disease, and nutritional deficiencies, most notably iron and zinc. Although most cases of yellow nails are not caused by an internal disorder, underlying medical problems should be ruled out if your nails have suddenly changed in color. Simple blood test.