It's estimated that 40% of people in the U.S. will experience symptoms of sciatica at some point during their lifetime. The third most common reason for visiting a healthcare provider is back pain. Sciatica is a condition caused by pinched sciatic nerves. In most cases, the spine is affected by a herniated disk or bone spurs, which are overgrowths of bone on the spinal bones. Nerves can also be compressed by tumors more rarely. Nerves can also be damaged by diseases such as diabetes.   Sciatica is commonly caused by age-related changes in the spine, such as herniated disks and bone spurs. The spine is more stressed when you are overweight. Working with heavy loads, twisting the back, or driving a car for a long time may cause sciatica. The likelihood of developing sciatica is higher for people who sit and don't move much than for those who are active. Nerve damage is more likely to occur in people with diabetes, which affects how the body uses blood sugar.