Understanding Black Nails Many people may wonder if black nails are related to cancer. While there is no direct and necessary link between the two, there are specific cases where black nails might be an external manifestation of cancer. This article delves into the phenomenon in detail: Subungual Hemorrhage When nails experience an injury or compression, the blood vessels under the nail, known as the nail bed, can rupture. This causes blood to pool beneath the nail plate, leading to a darkening appearance. Typically, this condition resolves on its own over time and does not require special treatment. Fungal Infections... Learn more