10 Signs you are drinking less water 1. Headaches that come out of nowhere 2. Dry lips that chap easily 3. Fatigue even after a full night's sleep 4. Dull, tired-looking skin 5. Trouble focusing or brain fog 6. Muscle cramps or body aches 7. Constipation or sluggish digestion 8. Bad breath even after brushing 9. Sugar or caffeine cravings 10. Mood swings or irritability