Having an epidural is not really painful. Patients report that it feels “strange”, like pressure in the back.
The anaesthetist employs a “loss of resistance” technique to know when the needle tip has reached the epidural space: a syringe is attached to the epidural needle, which is gradually pushed further below the skin in the direction of the epidural space. With his/her thumb, the anaesthetist keeps continuous pressure on the plunger of the syringe. When the tip of the needle reaches the epidural space, which has a lower resistance than the surrounding tissues, the plunger will suddenly drop into the syringe (“loss of resistance”).