Sciatica is a set of symptoms including pain that may be caused by general compression and/or inflammation of one of five spinal nerve roots that give rise to each sciatic nerve, or by compression or inflammation of the left or right or both sciatic nerves. The pain is felt in the lower back, bottom, and/or various parts of the leg and foot. In addition to pain, which is sometimes can be 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. The pain can be also be severe in prolonged exposure to cold weather.

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 inflammation of 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.