Sciatica refers to pain that radiates along the path of the sciatic nerve, which branches from your lower back through your hips and buttocks and down each leg. Typically, sciatica affects only one side of your body. Alternating heat and ice therapy can provide immediate relief of sciatic nerve pain. Ice can help reduce inflammation, while heat encourages blood flow to the painful area (which speeds healing). Heat and ice may also help ease painful muscle spasms that often accompany sciatica. Sciatica pain is caused by an irritation, inflammation, pinching or compression of a nerve in the lower back. The most common cause is a herniated or slipped disk that causes pressure on the nerve root. Most people with sciatica get better on their own with time and self-care treatments.