A primary cause of sciatica is a herniated or bulging intervertebral disc that compresses the nerve root before it joins the sciatic nerve. Several nerve roots leave the spinal cord and exit through holes in the sacrum to combine and form the sciatic nerve, which then passes between layers of the buttock muscles into the deep muscles of the back of the thigh. Sciatic pain results from the inflammation of the sciatic nerve and is usually marked by pain and tenderness along the course of the nerve running across the upper buttocks and the rear of the thighs.
Sciatica (or sciatic neuritis) is a set of symptoms including pain that may be caused by general compression and/or irritation of one of five nerve roots that give rise to the sciatic nerve, or by compression or irritation of the sciatic nerve itself. The pain is felt in the lower back, buttock, and/or various parts of the leg and foot. In addition to pain, which is sometimes severe, there may be numbness, muscular weakness, pins and needles or tingling and difficulty in moving or controlling the leg. Typically, the symptoms are only felt on one side of the body.
Although sciatica is a relatively common form of low back pain and leg pain, the true meaning of the term is often misunderstood. Sciatica is a set of symptoms rather than a diagnosis for what is irritating the root of the nerve, causing the pain. This point is important, because treatment for sciatica or sciatic symptoms will often be different, depending upon the underlying cause of the symptoms.
