Dark nails may be the result of fungal infections, the onychomycosis, which are the most common cause of dark nails. Nails can also become dark due to local knocks (traumas) or due to diseases that affect the whole organism in the case of several nails changing color.
Some diseases that can cause changes in nail color:
- kidney disease,
- chronic obstructive pulmonary disease (COPD),
- pleural effusion,
- cardiac insufficiency,
- Diabetes Mellitus,
- hepatical cirrhosis,
- Wilson's disease,
- bacterial endocarditis,
- peripheral vascular disease,
- nail cancer.
Nail color changes can mean the presence of various health problems. The dermatologist is the specialist indicated to diagnose and treat these problems.
Learn more at:
Can yellowish nails be a sign of disease?
Nail pain: what can it be and what to do?