What's wrong when your fingernails have lines?

I have black lines on few of my fingernails. How do I get rid of them?

• So I have black lines on my fingernails and I just absolutely hate it. I have to wear nail varnish everytime I go out because I don't want anyone to see them. At home I don't because my family already know. It has lowered my confidence a bit due to the fact my nails look so horrible because of the lines. I just don't know what to do to get rid of them. Does anyone have this? Or has anyone had it before? How did you get rid of it? Medication?

• Answer:

  With a rubber...I'm sorry I had to say it :D I would say always go to GP first, they will refer you to someone who can specifically treat you in hospital (normally a 6-8 week wait for the appointment). Don't worry about whether you are wasting the doctors time, this is what they are here for, and it is always better to be safe than sorry. I don't know and this is a guess, but it might be something to do with diet! Do you know if you are intollerant/allergic or have a deficiency in anything. This could very easily be the reason!