nail

what the cause of the nail has brown stripe

[Bhupinder Kaur, MD]

Hello,
Pitted brown spots in fingernails may indicate a skin and joint disorder called psoriasis. Reddish-brown spots can indicate a deficiency of folic acid, protein or vitamin C. It can also be due to melanonychia striata which are harmless dark lines on the nails caused by melanin, a pigment.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your dermatologist. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.