When the pain shoots along your sciatic nerve, through your buttock area and down the leg it tend to be much more painful than typical mechanical back pain as the nerve itself is directly aggravated.
The pain typically is one sided and can be caused by a joint problem, a muscle spasm and occasionally and injury to the disc.
I focus on being really clear as to the nature of which tissue is causing the injury , rather than assuming that sciatica is caused by disc bulges , which is what a google search tends to suggest ( as a worst case scenario). Treatment can then be focused on quickly getting this area out of pain.
Short term relief suggestions
Inflammed nerves tend to respond better to ice than heat. The ice is applied to the area of the spine that hurts rather than the muscle though. Anti –inflammatory medication can also reduce the nerve irritation, and most GPs tend to prescribe muscle relaxants to help. Heat on muscles can also help. Try to reduce the time you sit. Avoid lifting with lying down combined with regular movement ( walking tending to be more beneficial)