I am 29 years of age. I have had a reddish/brownish extremely thin line under my left thumbnail since 2003 or 2004. But this line kept on appearing and disappearing so I did not take much notice. However, since last one or two years, I have noticed that there has been an increase in this number and now there are 3 thin lines of different lengths close to each other under the same nail. What is worrisome is the fact that there are signs that more would be visible in future. It hurts on pressing that portion of the nail. A few days ago I noticed almost dot sized appearance under the fingers of my right index and little fingers which disappeared after cutting the nails.

I am really worried. What is treatment for this? I have photograph of my infected nail but since posting of images directly is not permitted here so I cannot do it.
Please advise as soon as possible.