My Wrist Has Been Hurting A Lot. There Is No

My wrist has been hurting a lot. There is no swelling or redness but when I bend it either way it hurts a lot or when there pressure on it. This happen a couple months ago too where it hurt even to have it lay in certain positions. It is my left hand and I am right-handed. The pain is from the right side under my thumb, where the wrist starts, and goes down about two inches. Do you know why?