What Treatment Is Suggested For A Large Bruise On The Back Of Right Hand?

about 5 days ago I developed a large bruise on the back of my right hand. There was a large knot in the middle of it. The next morning the swelling went down and bruising seemed not as bad. Yesterday the bruise was back only larger and there is a small nodule in the center of the top of my hand. My hand is achy and sore to the touch. I did not hit it on anything that would explain how I got this. Should I be concerned?