Hi, i am suffering from a bad back - in the thoracic area on the right hand side. i have felt numbness in my legs all day and nausea ..

Get check up: Unless you know the cause(such as lifting or injury), you should get a medical check up. I am more concerned about numbness in your legs. This could be due to a spinal compression which can be caused by a tumor or defect in the vertebral disc. You should get a check up by a neurologist or your PCP, soon. If the legs start getting weaker, then go to a ER.