In rare cases, a black toenail may be caused by melanoma Melanoma is the most aggressive form of skin cancer Melanoma causes the skin to develop one or more patches of dark, irregularlooking3 Thickened nails There are a few reasons for having thick nails but they are commonly caused a fungal nail infection, but can also result from psoriasis and reactive arthritis (a painful form of inflammatory arthritis) Yellowish, thickened, slowgrowing nails can also indicate lung diseases 4 Loose nails When the fingernails become loose and can separate from the nail bed, it may3 Melanoma The most severe form of skin cancer, melanoma, can occur anywhere you have skin on your body, your toes included Melanoma usually appears as a dark brown to black unusually shaped spot, and when it occurs near or under the toenails it can look like a long dark streak through the nail With melanoma, the surrounding toe skin may
Common Foot Problems
How to get rid of black spot under fingernail