A few years ago I had sever dehydration and needed fluids by IV. Since then, during and after physical labor, I have had a tendency to sweat heavily and start cramping after a couple of hours. This not alleviated by fluid intake. Water, sports drinks, bananas, or other attempts to fix this have failed. I m 59 and have labored all of my life. Help? I have never been told that I have low potassium or any possible chemical imbalance,