There is no shortage of things that can be done to help relieve some of the pain associated with sciatica, and I would venture to say that more people try to alleviate sciatica than actually cause it by not knowing how to treat or cure it.
The most common thing people try to do is rest. This can be useful for the short term, but the longer that you stay in bed the weaker your back becomes. It is better to have a few days away from pain than to let weakness set in. It is a good thing to have a few days away from the pain, but if you stay in bed too long then your spine will become weaker. Weak spine means weaker back.
Another thing people try to do is exercise. This will help to strengthen your back but it is a very poor long term solution. It is much better to strengthen the weak parts so that they do not get weak. It is much better to strengthen the parts that have been damaged then to strengthen parts that are healthy. When weak bones are damaged and this causes pain. It is very important to strengthen those parts that are healthy and not damaged; but if those parts are also weak then this again will cause pain.
So the answer to relieving sciatica is to cure the sciatica as quickly as possible and then start to treat the spine. This will cure the back and allow the pain to be bearable. But it is not good to wait on cures for sciatica until you start to feel pain. So once you feel pain, start the treatments immediately as to cure sciatica as quickly as possible. It is better to cure the sciatica quickly then to cure the back and not feel any pain.