What are the signs of fingernail problems? Fingernail symptoms include a variety of irregularities with the fingernails, such as changes in the color, texture, shape, size or structure of the nails. These abnormalities can arise from a number of systemic causes, including disease, infection, injury, nutritional deficiency, or poison. Fingernail abnormalities may also be caused by localized inflammation or infection. Specific types of fingernail abnormalities include Beau’s lines (trenches that run across the fingernail), koilonychia (concave, spoon-like fingernail shape), leukonychia (white spots appearing under the fingernail), onycholysis (separation of the fingernail from the underlying skin), pitting (sporadic pits in the fingernail), ridges, yellow nail, and clubbing. Clubbing is a condition in which the nails curve abnormally due to thickening of the skin beneath the nails. It is seen in a variety of diseases in which the oxygen levels in the bloodstream are abnormally low, such as diseases of the heart and lungs. While fingernail symptoms are not typically a serious problem, some fingernail symptoms may be associated with a symptom of a serious systemic infection or disease within the body. For example, Terry’s nails refer to whitening of the fingernails associated with diabetes, heart failure, and liver disease. The occurrence of localized inflammation or infections of the fingernails, often caused by bacteria or fungus, can be reduced through proper care and grooming of the fingernails and by keeping the skin around the fingernails clean and dry. Some fingernail symptoms can be evidence of a serious condition. Seek prompt medical care if you notice changes in the color, shape or texture of your fingernails or the skin around your fingernails, or if you experience fingernail pain, have pus around your fingernails, or experience persistent fingernail infections. If your fingernail symptoms are persistent or cause you concern, seek prompt medical care. Seek immediate medical care (call 911) for serious symptoms, including coughing up mucus, difficulty breathing, high fever (higher than 101 degrees Fahrenheit), and watery diarrhea containing pus or blood, as these could be signs of a life-threatening condition.