Yesterday I became very dehydrated, and I was up a lot during the night with heartburn trying to figure out what my problem was. When I was standing, I felt ok, but when I lay down the heartburn came back. I ended up sitting in a chair trying to snooze.
When my body needs water, I become thirsty like most people do. If I still don't drink enough water, my body advances from thirst to heartburn. That is, after I've felt thirsty, my dehydration will cause me to have heartburn. I drank very little yesterday and didn't realize that I had become dehydrated. About two hours after I went to bed, I woke up with bad heartburn. My normal treatment for heartburn is to drink aloe vera in a great tasting drink, but that didn't help. I tried it two more times with no success. I finally realized the heartburn was caused by my being dehydrated. I drank two or three glasses of water and went to bed and slept fine. I've made sure that I drank sufficient water today, and I feel fine.
I should have realized sooner that the heartburn was caused by dehydration, but I don't get heartburn very often, and it took me a while to figure it out.
General recommendations for runners are to drink when you feel thirsty. And, drink enough fluid that your urine is either clear or has a slight color. Be careful, though, that you don't drink too much water. Typically, a person needs 6-8 glasses per day, but that varies with the individual. Some doctors say that should be 6-8 glasses of water, while other doctors say it can be any fluid.