Epidural injections are used for chronic sciatica where the source of your pain is from a slipped disc which is pressing on a nerve root. The injection is given into the epidural space which is between the spinal sac and the inside of the spinal canal.
This makes sure the drugs injected flow up and down the spine to coat the nerve roots near the injection site.
You can have this done under general or local anaesthetic. Ive had it done both ways but would not have a general again.
The drugs used for this injection is a mixture of a local anaesthetic and a steroid, which then relieves your pain.
The steroid is insoluble so it stays where its injected and you therefore have no side effects like something taken by mouth.
You can feel quite delicate and it can feel painful for the first day or two but when
the effects kick in, it can last from weeks to even months, so its well worth having done.