You should see your doctor as soon as possible if as well as back pain, you have a high temperature, redness or swelling on your back, pain down your legs and below your knees, numbness or weakness in one or both legs or around your buttocks, loss of bladder or bowel control(incontinence), constant pain, particularly at night and/or pain that is getting much worse and is spreading up your spine. These symptoms are known as red flags. It's important to seek medical help for these symptoms to ensure you don't have a more serious underlying cause for your back pain.
Attribution: BUPA