What is deciding factor for surgery or not with bulging disc?

Symptoms. The main factor would be symptoms - either pain or nerve compression leading to weakness, numbness. Usually after conservative management and epidural injection is symptoms persist, then surgery should be considered.
Several. Surgery for a bulging disk is an option for patients with clear cut, pinched nerve symptoms that are refractory to nonsurgical treatments. A spine surgeon can determine whether a patient has the requisite findings to qualify as a surgical candidate. From there, the decision for surgery is in the hands of the patient. The decision for surgery is shared between the surgeon and patient.