I have brown discoloured skin on the bottom of my fingers. the skin texture is the same and there is no itching. i don't know what it is.

Difficult to say: You're young and probably healthy so that shortens the list of possibilities. It's very hard to guess without pictures but my first thought is a very light, early fungal infection that is keeping your top layer of skin from sloughing properly which makes it look darker. Ask your pharmacist for an over the counter antifungal cream, use it 2x daily for a week and see if it doesn't improve.