There are many reasons for yellow nails, for example, certain male patients have a long-term habit of smoking and their nails may be yellowed. In addition, certain people have a disordered diet, such as a deficiency of vitamin A, vitamin E, and minerals such as zinc, calcium, phosphorus, and iron, which can also cause yellowing of the nails. There are also certain people who have yellowing nails due to fungal infections in their hands, if the fungal infection may destroy the matrix of the nails, such as the nail bed. In addition, some people who have liver system diseases such as jaundice may also cause yellowing of the nails, so when yellowing of the nails is found it is recommended to go to the hospital for timely treatment to prevent further expansion and spread of the symptoms.