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! 


nature walk

Like all other animals, humans gravitate towards the things, places, and features that resemble those present when we evolved. As such, we have this innate tendency to seek out natural spaces. Our bodies sense that we have a past there, and strongly prefer it to any other setting.

Evidence for this phenomenon comes in the form of preferences. Consider our relatively-slim range of preferred temperatures. Consider how, in visual spaces, we prefer to see, but not to be seen – a combination of prospecting and refuge-seeking behavior that yields, ultimately, comfort. We love Nature so much that we bring it into our homes, in the form of pets and houseplants. The omnipresence of Nature, and our careful cultivation of it, must convey some benefit. Otherwise, Evolution wouldn’t have preserved these behaviors.

Observe: the profound, untold health benefits of a simple walk in the woods.

For one, nature walks seem to have memory-promoting effects that other physical activities can’t replicate. In a study by the University of Michigan, students who walked in Nature reliably performed up to 20% better on brief visual memory tests than those who walked through the center of town. The same study was replicated for individuals with Major Depressive Disorder (Berman, Kross, et al.) and produced even more shocking results. They seemed to disproportionately benefit from Nature walks – over 53% of the sample group exhibited a significant increase in memory span after the nature walk, relative to an urban walk.

Past this single example, a meta-analysis of 10 other studies on the subject (performed by the same authors as above) showed that the mentally ill seem to benefit from disproportionally exposure to Nature. The presence of water resulted in even more substantial improvements. And while the depressed participants also showed marked increases in mood, the mood effects in Berman, Kross, et al. did not correlate with the memory effects, suggesting separate, biophysical mechanisms are at work.

An example of those biofeedback systems: Nature changes our stress response in measurable ways. Tons of researchers have observed hormonal changes brought on by Nature – with a powerful impact on the cortisol system. Study after study shows forest environments reduce cortisol, decrease heart rate, and tame blood pressure. One intensive study on 280 Japanese citizens found that forest walks resulted in a decrease of cortisol of around 15%, a reduction in heart rate of 4%, and a dip in blood pressure of about 2% for nearly all participants. Even among office workers, a window view of Nature seems to result in lower stress and higher job satisfaction.

But the benefits don’t stop there. At this point, the power Nature has over us seems to take on a supernatural tone.

Japanese traditional medicine has, for many years, considered forests to be a form of preventative medicine. “Shinrin-yoku” or “forest bathing” is a popular, oft-referred therapy for the many residents of Japan’s highly-urbanized central region. Clinical research on the practice is still in the earliest possible phases. But preliminary studies yielded such exciting outcomes, it became impossible to ignore the power of the forest.

Long-term residents of areas with greater forest coverage were found to have much lower cancer mortality rates than their urban counterparts. There are thousands of confounding factors making it difficult to establish a causal relationship – but the signs are there. When we analyze the blood of forest-dwellers, they have demonstrably higher levels of proteins known to target and kill cancer cells. They also seem to have much higher immune functioning, in general. Hopefully, in the next 5-10 years, we can discover precisely what’s causing the improvement. Until then, we should simply trust the trees. When it comes to health, it’s less important that we know how this occurs and more vital that we experience it for ourselves.

But what about city-dwellers? Are we simply supposed to accept that we might have a diminished quality of life?

The good news is: you don’t need an entire forest to reap most of these benefits. Parks convey many of the same effects – especially for nature-starved urbanites. Countless studies are proving this. Take the Dutch study Maas et al., for example. Researchers considered a sample size of over 250,000 city dwellers. They discovered that mere proximity to a green space had significant impacts on perceived general health – meaning that city dwellers feel better simply knowing they have access to natural areas.

So, the next time you’re feeling crummy, walk around some trees. That green space isn’t a luxury; it’s a necessity. And if you’re not so fortunate as to have immediate access, it’s probably closer to you than you think. Regardless, it’s always worth the journey.

You’re going home, after all.