What causes blackening of the nails?
Disease description:
Sometimes you may suddenly notice that your fingernails have turned black. The nail may darken from the base or have localized black spots or black lines. Does this mean there is a serious health problem? What exactly is happening?
Doctor's answer (1)
Dr. Liu Wenmin
Black discoloration of the nails may have several possible causes, specifically including:
1. Trauma: If the nail suffers an impact or pressure leading to ruptured blood vessels and blood accumulation under the nail bed, it can form what is called a "hematoma," causing the nail to appear black. This condition is usually accompanied by pain, but the black color will gradually fade over time.
2. Fungal infection: Conditions such as onychomycosis (fungal nail infection) can cause color changes in the nail plate, potentially turning it grayish-black, and may be accompanied by nail thickening and deformation.
3. Nail matrix nevus: Excessive melanin production from a nevus in the nail matrix can be incorporated into the nail plate, forming black streaks on the nail. These streaks are usually regular, symmetrical, and evenly colored.
4. Medication or chemical exposure: Certain medications or prolonged exposure to some chemicals may also cause nail color changes.
5. Malnutrition: A deficiency in vitamins and minerals, in particular, can affect nail health and lead to abnormal coloration.
6. Melanoma: A malignant melanoma located at the base of the nail or beneath the nail bed can cause the nail to darken rapidly. The discoloration is typically uneven in color, irregular at the borders, and may even be accompanied by ulceration, exudation, or other symptoms. Immediate medical attention at a hospital is recommended.
