well I have only been vaping for about a month, and the whole time I was vaping this past month I was using prefilled cartomizers from blu at 16mg. Well I bought some juice to refill them myself, and got 18mg. I have been vaping about a week and 1/2 at the 18mg as much as I vaped at the 16mg. I noticed I am feeling lightheaded and dizzy a little bit throughout the day. If I put the ecig down and don't touch it for an hour then I start feeling a little better, and I drink water as well. Could this dizzyness have to do with the fact I upped the nicotine level in the juice? should I go back down to 16mg? My body just doesn't seem to cope with it. and the juice I bought is vg base, from Johnson Creek, the same e juice they use in the blu cartomizers so I know it's not an allergy.