Arm hurts.Why and how can I help myself ?

For several days

sore left hand at the bend in the wrist. Started to hurt after leaned on his hands ( whole life so I do, but it is a pain in his left wrist began to torment more recently). The right hand does not hurt, only the left. The last time so it was a couple of months ago, then helped the wearing of woolen thread on the left wrist, but now and this tool does not help. Why can hurt his left hand at the crook in the wrist and how you can help yourself ?(Please do not advise to go to the doctor - does not help. )