The problem arises when you want to become more than friends. How do you approach your friend? Should you risk your friendship? What if they don't feel the same way?
Some people chose to keep their feelings a secret from their friend. They are afraid that if they tell their friend how they feel, and their friend doesn't feel the same way, that they will lose the friendship. It is certainly worth considering.
The best way to handle this situation is to be honest. You should tell your friend in a very casual way that you have been thinking about your friendship and you think that you might have feelings for them that extend past friendship. You should tell him or her that you do not want to pressure them or make them feel uncomfortable, but that you felt it was important that you were honest. Then let your friend speak.
If you are lucky, your friend will tell you that they feel the same way. But what if they don't? If they do not reciprocate your feelings, you need to make it very clear that it is OK with you. After all, you were friends first and you don't want to lose that person from your life. Do not pressure them or make them feel bad for their decision. Remember, it is not easy to reject someone, especially someone you care deeply for.
If you don't feel you can talk to your friend one on one, then you might want to consider involving a third party. Have a mutual friend speak to your friend to find out if they have ever given thought to being “more than friends” with you. This way you know if it is worth a shot.
Either way, friendships aren't often ended because someone confesses their true feelings. There might be an initial period of awkwardness as you both deal with your confession. However, this is likely to pass and the friendship can continue as normal.
If your friend likes you too, then congratulations! Relationships that are built on a strong foundation often last the longest.