I’ve googled ‘sword wounds to the side’, ‘surviving a sword wound’, ‘treatment of sword wounds in medieval times’. I’ve gone through the tags on here that I thought might provide answers but I didn’t see anything particularly specific to what I needed. Maybe I’m just bad at google-fu.
EDIT: Woops! The character in question is wearing a light leather jerkin. The sword I believe is a broad sword (not for certain but I think its right) and the blow would be a glancing as someone shoves the frontal assailant before they can get a full hit and would be directly under the ribs (the fleshy area on the side).