I have very faint brownish vertical lines on my pointer finger nail and thumb nail (right hand). what does this mean? should i go to my doc?

Need more info: It's hard to make a diagnosis without actually seeing the problem. They could just be hemorrhages or something else. See your family physician or a dermatologist.

Does not cause conce: I doubt that these brown lines of any consequence right now. So you can watch them(Take a photo on your cell phone) and monitor for any change over a period of 3-6 months. Unless they increase or any skin lesions appear anywhere over your body, you can ignore them as harmless.