Your urine becomes dark yellow
The color of your urine is an important indicator of health. When you drink sufficient amounts of water, your urine is pale yellow. If it gets dark yellow and appears more concentrated, this is a sign you need to refill on water. Also the frequency of urination matters. If you haven’t been to the toilet for 2 hours or more, this means you haven’t been drinking any water and should replenish.
You feel dizzy
Since blood is mainly made of water, dehydration also causes a drop in blood pressure. When you have low blood pressure, you can start feeling wobbly.
you experience brain fog
It’s not uncommon to have cognitive difficulties when you haven’t drunk enough water. Brain is made 90% of water and brain cells and nerves react badly to water loss. You can start feeling sluggish, and experience problems with concentration and memory.
You have a headache
Headaches are often caused by dehydration (as I mentioned in my post about the top 15 causes of headaches). When the pressure in your blood vessels drops, it makes it harder for the heart to pump enough oxygen to the brain, which results in a headache.