Instead, when we speak of large white spots, it can be a symptom of kidney failure or cirrhosis. Bitten nails (nail biting). In addition to the aesthetic problems caused, nail biting can alter the shape of the teeth or affect nail health: these midogen do not grow well by nibbling continuous to which they are subject, and create microtrauma throughout the entire nail bed (the part that is under the nails) and altering their anatomy. also cause damage around the nail, small wounds that cause the finger to swell and hurt. Lack of protein.