Theres a thin black line on my right thumb nail thats been there for a while. Its not like a stain that goes away it grows with the nail. I looked online and read that it could be a sign of melanoma. Do you think I should be worried about this?"
Probable diagnosis is psoriasis,eczema,hypothyroidism,injury,rheumatoid arhritis, melanonychia,Hiv,cancer and anemia etc. vit b12 deficiency .Most causes of black lines do not require treatment..Melanoma is a exception.Treatment of the underlying cause .