Dehydration, which causes many health problems on its own, can occur as a result of drinking too much alcohol. It lowers the level of the anti-diuretic hormone, which is used by the body to reabsorb water. You lose more fluid than necessary. Diet sodas with caffeine can have the same effect because of artificial sweeteners such as sucralose and aspartame. Dehydration causes bad breath, sugar cravings, fatigue, dizziness, and headaches.