A herniated disc's symptoms depend on the exact level of the spine where the disc herniation occurs and whether or not nerve tissue is being irritated. A disc herniation may not cause any symptoms. However, disc herniation can cause local pain at the level of the spine affected. If the disc herniation is large enough, the disc tissue can press on the adjacent spinal nerves that exit the spine at the disc herniation level. This can cause shooting pain in the distribution of that nerve and usually occurs on one side of the body and is referred to as sciatica. For example, a disc herniation at the level between the fourth and fifth lumbar vertebrae of the low back can cause shooting pain down the buttock into the back of the thigh and down the leg. Sometimes this is associated with numbness, weakness, and tingling in the leg. The pain often is worsened upon standing and decreases with lying down. This is often referred to as a "pinched nerve." If the disc herniation occurs in the cervical spine, the pain may shoot down one arm and cause a stiff neck or muscle spasm in the neck. If the disc herniation is vast, it can press on spinal nerves on both sides of the body. This can result in severe pain down one or both lower extremities. There can be marked muscle weakness of the lower extremities and even incontinence of bowel and bladder. This complication is medically referred to as cauda equina syndrome.