Selective Nerve Root Block is the procedure of injecting a small amount of steroid and medicine to numb the area around the specific nerve. The process serves a two-way function. First, it helps the doctors to know which roots, nerves are affected, and second it also acts as a therapy relieving the pain. Therefore it is both a diagnostic and therapeutic measure. Selective Nerve Root Block is more commonly helpful in treating problems in Cervical, thoracic, and lumbar back areas problems. The Selective Nerve Root Block performs the mechanisms like inhibiting the secretion by enzymes that cause irritation and pain, blocking the fibers and decreasing the permeability of nerve fibers to receive blood that reduces pain. The process of injecting the medicine into the body involves cleaning the skin to prevent infection, injecting a dye that helps to locate the target nerve. Selective Nerve Root Block yields more fruitful results for the people practicing strengthening exercises and therapeutic measures, as suggested by the doctors.