Contemplating if i should go to the emergency room for a lump in my back that i believe cause great pain throughout my lower back, butt, & left leg?

Red flags: Back pain most often is related to muscle strain or sprain. Lumps that you can feel are usually from a muscle spasming. Red flags that mean your lump and pain might be caused by infection or cancer include a fever, history of cancer, history of IV drug abuse, weakness in your legs, or losing control of your bowel or bladder. If you have these, you need to go to the er.

Yes and no.: If you are really concerned about the lump then you should go to the er, but likely they will refer you to your primary care unless you have weakness, numbness, bowel and bladder loss, infection, or obvious cancer there. You will probably require a workup including x-rays, MRI and consultation with spine surgeon. Good luck!

No Need for ER visit: Pain in the distribution as you suggested describes the pattern of the nerve that travels in the leg called the sciatic nerve. The sciatic nerve is not the cause of the pain source, it is the result of an irritated nerve typically in the lumbar spine (low back) which are caused by herniated disks, spinal stenosis or degenerative disc disease requiring further evaluation by a spine specialist.