Sciatica. The sciatic nerve is the longest nerve in your body which begins in your spinal cord and moves down into both legs. You may experience pain, numbness or weakness when this nerve becomes irritated. Smoking and diabetes can increase the likelihood of sciatic nerve problems, along with twisting movements, heavy lifting and sitting for long periods of time. Staying in bed or avoiding activity could make this condition worse. Cold compresses are recommended after an injury and changing over to heat after the first few days. Over-the-counter medications can also help with pain and swelling.