Though nerve root block is a safe procedure, it carries its own risks and complications, which include injury to the nerve root leading to temporary or permanent deficit or worsening of pain with or without tingling or numbness or involvement of bowel or bladder. Multiple nerve root blocks done in single sitting can lead to weakness and inability to walk for several hours after the procedure.
Occasionally an injection into the blood vessel can be dangerous for patients general health and well being. Injection in the vicinity of the nerve root may lead to bleeding with hematoma formation and cauda equina syndrome which may need urgent surgery to take care of the compression.