Nausea and dizziness can both be symptoms of low blood sugar, or, as the previous poster noted, high sugar
levels. If your
glucose levels are running too high, usually the person shows the typical symptoms of unusual thirst and fatigue. If low, dizziness, inability to concentrate, headaches, yawning for no reason, shaking hands, irritability or depression, sleepiness, or a dry mouth or eyes can be present.