I also have that problem right now. My right side is significantly larger than the left. The dr. said it could just be a goiter that doesn't effect anything, or it could be cancerous. I am scheduled to get a biopsy tomorrow and if it's cancerous they suggest having whole thyroid removed. If it's not cancerous, there are medicines you can take to try to shrink it and regulate the hormones. So it depends on what they find in there. Hope this helps.