For the past 3 days i keep having severe pain on the bottom left of my back. my thigh feel tingling. what should i do? go to the drs or er?

Lumbar pain: Pain in the back can be from either a muscle, a bone, or a nerve disorder. The tingling is a sign of some neurological process. Together with back pain, this is often seen in problems involving the lumbar nerve roots. This can result from a herniated disc, a bone spur, or other processes. Weakness is a more worrisome symptom that would require more urgent attention.