4 Surprising Signs You Might Actually Be Dehydrated Here are 4 signs you might be dehydrated and need to drink more water. 1. Brain Fog, excessive fatigue and irritability. 2. Weight gain. 3. Gas and bloating. 4. Stomach ulcer. As a general rule check the color of your urine. It should be mostly clear with a tinge of yellow. Do you drink enough water in a day? Most people do not like water, how do you make water ‘fun’ for you?