Sciatica pain is caused by irritation, inflammation, pinching, or compression of a nerve in the lower back. The most common cause of this condition is a herniated or slipped disk that causes pressure on the nerve root. This video explains all the details about this common disease. 0:00 Definition 0:37 Relevant anatomy 2:32 Clinical features 3:21 Provocative tests 4:22 Causes 5:28 Treatment