Foggy, Hungry, Angry | The Consequences of Dehydration

Foggy, Hungry, Angry | The Consequences of Dehydration


If you’re thirsty, you’re already dehydrated.


Water is absolutely essential. The right amount keeps the body running; the wrong amount can kill us. It plays a critical role in every step of every process necessary to live – digesting our food, flushing out toxins, regulating temperature, and maintaining brain function. The ratio of water to electrolytes – like sodium and potassium – must remain within a specific range of concentration. All our cells rely on the equilibrium of these chemicals.


Life began in the sea. Tens of millions of years later: here we are. Still unable to survive on land without carrying an enormous amount of salty water with us. And we’re constantly losing it.


Dehydration usually isn’t a severe condition. With correct water levels being such a basic need, humans have evolved to be very good at keeping it in check. It’s recommended to drink 11-15 cups of water a day – and you can undoubtedly drink that much without consequence – but we already get most of that water from our food. 


Still, dehydration is no laughing matter. It comes on rapidly, and the symptoms grow exponentially worse with time. Not only is it physically uncomfortable – it affects the way the brain works, as well. If you’re not drinking enough water, your body slowly loses its ability to perform optimally – piece by piece, system by system.


Mild dehydration can make us tired and irritable – dampening mood, increasing fatigue, and causing cluster headaches. As you dry out, it can lead to decreased cognitive performance. Recent literature suggests that just a 1–2% body water loss can impair reaction time. The brain and nervous system struggle to send electrical impulses when the water level falls too low.


Most people can function through mild dehydration, losing up to about 3-4% of their total water volume before experiencing the more severe symptoms. But even this seemingly-negligible lack of water leaves a person disoriented, dizzy, and nauseous. 


But that’s not all: if you’re not drinking enough water, it can trigger hunger pangs – making it harder much more challenging to lose weight. In that way, overheating can lead to overeating.


Dehydration works along the same neural pathways as hunger. When you’re hungry, your body releases a hormone called “ghrelin” into the bloodstream. Ghrelin triggers a signal in your brain that tells you to eat. Your stomach also grows in size and sends out acid to help break down the food. The more ghrelin in the bloodstream, the hungrier you feel. And when you dry out, your brain triggers the ghrelin hormone once again. But the gut only hears “I need sustenance” – not “I need water, specifically.” We’re often unable to differentiate between the two sensations. So, if you’re feeling hot or tired, not drinking enough water, or all of the above: know that your body’s going to crave food, too.


The problem is that many people aren’t aware they’re dehydrated until it’s too late. They’ve already reached the point of diminished control over their mental and physical functions, but they don’t realize it because they’ve become so accustomed to feeling crummy.


So drink more water! Chances are, you could use a little more, and it’s almost impossible to over-hydrate (although it can happen, ironically causing many of the same problems as dehydration due to electrolyte imbalance in the other direction.) An excellent way to start getting more is simply drinking a glass with every meal. Water aids with digestion and helps you feel fuller, faster. And if you’re exercising regularly – drink more. Supplement with electrolyte powder if you start to feel foggy. But ultimately, trust in your body’s signals. It’ll tell you when things are out of whack.


Just remember: by the time you’ve lost more than 15% of your total body water, cells begin to rupture. And around 20%, we die. Keep an eye on it! 

Saul Roberts