What’s your favorite drink? Soda? Wine? Well, my favorite is water, but did you know that drinking too much water can poison you? It’s true! The reason that drinking too much water can poison you is that over time your sodium levels will slowly go down and this can make you have headaches, nausea, and fatigue. The average sodium level is 135 to 145 milliequivalents per liter. This is why drinking too much water can poison you.