Clean, well- polished nails are always appreciated. If you have yellow, unhygienic nails then it will not only affect your health but will also create a bad impression on someone you meet for the first time. A lot of people don’t realize how and why their nails have turned yellow or brittle which can also be a sign of an underlying disease. It is said that your nail is a reflection of your internal health, therefore, if you are having yellow and dirty nails then there are chances that your body is sending signals which need immediate attention.