Severe nausea after walking

Hi , I haven't posted on here in quite a long time, but I'm having a hard time with severe nausea , usually right after walking too far or doing too strenuous activity .
I get it whether or not I eat and it has nothing to do with eating too much or eating with Water so I was curious if anybody has gone through this before ? I had surgery about 13 years ago and at a typically normal weight

I'd try upping your electrolytes.

More fluids, more electrolytes.