Nail Disorders as clues to systemic disease

Disorders of the nail unit can provide important clues to underlying systemic diseases. Onychodystrophy or nail abnormalities include altered nail color, shape, or texture, with morphology and growth patterns often related to local anatomic factors such as edema, vascular supply, and neurologic innervation. Associated pain or loss of function can also affect daily activities. Because nail changes may be due to a range of systemic diseases, we chose to provide a systems-based broad overview of the common nail findings in patients with internal disease.