How do you switch from one blend space to another blendspace using blueprints and variables?

Hello everyone, just a quick question as I am learning unreal engine… how would I switch my characters blendspace according to a variable… is it state machines I have to learn and look up or can this be done through blueprints in the player characters event graph? Example: my character just has a normal blend space with run, walk, jump etc… I want it to switch when she is getting low on health (Which for me is a Float Variable) to a blendspace I have set up with the same animations but obviously her walking and running is an injured version… Also would like to implement this as I would like her to be walking with a torch as well… just have no idea how to switch blend spaces assuming it is blendspaces I will have to switch… Any help greatly appreciated.

State machines and variables is the way to go about it.
You can find tons of tutorials on state machines. The gist is you define how to enter and exit states within a state machine. You can have those states be changed by variables just like you are describing.