As per your explanation I would suggest to check whether there is any nodule or bulge on your wrist on back side where it pains. Or whether pain is at one pointed area. It is called as dorsal wrist ganglion which happens due to over use of wrist extensor by using too much of key board or even some time mouse. The treatment is visit a ortho or physio they may take x ray to check there is no other abnormality. And physio will give treatment like ultra sound to reduce pain and produce healing effect as well to reduce inflammation. You can also do ice massage on local pain full are as well use hot pack in between this will also give you relaxing sothing and pain relieving effect. Hope it was useful. Take care.