Thankyou sir for giving me the valuable advice
Hello,
Horizontal lines running through the nail, on the other hand can sometimes indicate an underlying medical problem . Occasionally, fungal infections of the nail will cause similar lines and dark stripes may sometimes be a form of skin cancer that affects the nail bed, called subungual melanoma. It's therefore important that your doctor checks it to rule out melanoma.
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 doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.