на нервной почве?

What is на нервной почве?

Literally it translated as "nervous soil" or "nerve soil" but when I typed it into google images it shows pictures of rashes (which is in synch with the video I'm watching. They are discussing rashes)

But how does nervous soil mean rash? Is this an idiom or something?

Any help is appreciated. Thanks

'на нервной почве' is idiom meaning 'due to bad mental condition'. for example state of strong worry can induce rashes and other bad health conditions.
'soil' of course is incorrect. it's more like '...grounded in bad mental condition'.