Before Thirst:

Takeaway: Feeling thirsty isn’t the only sign of dehydration.

Dehydration is no laughing matter. In fact, numerous studies have found strong links between dehydration and impaired mental and physical performance.

If you think dehydration doesn’t affect you, think again. Estimates suggest that three-quarters of American adults go through their day in a state of at least mild dehydration.¹ This can result in anything from slight mood changes to impaired ability to focus, causing serious mistakes that may have otherwise been avoided.

What Constitutes Dehydration?

If you’re going to recognize dehydration before it progresses too far, you must first understand what it is and how it happens. Dehydration is defined as an inadequate amount of fluids in the body, which happens when fluid is lost faster than it is replenished. Mild dehydration is defined as a 1.5 percent loss in the body’s water volume, and symptoms gradually get worse as water loss progresses. A loss of 15 percent is enough to cause death.² But Activities and strenuous tasks, especially in hot and humid environments, can cause the body to lose fluids quickly. If those fluids aren’t replaced, dehydration can set in.

Water is essential in the body. It’s a transporter flushes out toxins, aids digestion, supports joint and eye movement, and keeps the skin healthy, to name a few. So long as you’re properly hydrated, your body has no issue carrying out these routine functions (for more details, check out Electrolytes: What They Are and Why They Matter for On-the-Job Hydration).

Contributing Factors

We lose an average of 2.5 liters of water each day just through our normal bodily processes like breathing, urinating, and sweating. But those who engage in hard, physical activities can experience a much greater fluid loss.³

There are four main factors that contribute to dehydration:

1. Outside activities in the sun, heat, or humidity can increase perspiration and cause you to lose fluids quickly. Heated indoor environments can have the same effect. Altitudes of 8,200 feet or greater tend to increase the frequency of urination and quicken breathing, which also uses up more fluids.

2. Physical activity. Strenuous activities that cause you to sweat and breathe heavily contribute to greater fluid loss, which can lead to dehydration.

3. Illnesses and health conditions. Vomiting and diarrhea can quickly dehydrate you, while frequent urination from conditions like diabetes can cause you to lose more fluid than you might expect.

4. Diet. Even though you’re consuming liquids, drinking alcohol, coffee, and sugary sodas actually contributes to the onset of dehydration rather than helping replenish the body’s fluids. Caffeine can cause you to urinate more frequently, while the body must work extra hard to process heavily sweetened drinks.

While these factors and their impact may vary from person to person, absolutely everyone is at risk of dehydration.

How Dehydration Impacts You

Dehydration can have serious effects. Numerous studies have shown that even mild dehydration can significantly impact cognitive and physical abilities.⁴ Wouldn’t consider any and all of your tasks to require focus, concentration, precision, and even good hand-eye coordination? A slight loss in focus can negatively affect your ability to do these things.

To drive the point home, a 2015 study out of Loughborough University examined the driving abilities of volunteers who were dehydrated. Shockingly, the study found their performance to be just as poor as people who completed similar tests while legally drunk, due mainly to a reduction in concentration and a slower reaction time.⁵

It should come as no surprise, then, that dehydration can also be a major drain on your day. Research suggests that just 2 to 3 percent water loss is enough to decrease energy levels by as much as 20 percent. If 75 percent of American adults really are chronically dehydrated, addressing the issue has the potential to reverse those results.

Dehydration Symptoms to Watch For

Unfortunately, most people wait until they’re thirsty to take a drink. But the truth is that if you’re feeling thirst, you’re already in a slightly dehydrated state.

Catching dehydration early is key to addressing it before it has an impact on cognitive and physical function. Luckily, there are many other signs you can be on the lookout for.

Headaches are an early sign of potential dehydration. They are often accompanied by tiredness and light-headedness and can be remedied within about 30 minutes by drinking a tall glass of water.

Urine color is one of the easiest superficial ways to assess hydration level. Clear to pale yellow urine is a sign of proper hydration. A light honey color suggests that you should re-hydrate soon, and darker yellow urine is a sign that your body needs hydration immediately.

Excessive sweating isn’t a symptom of dehydration, but it’s a sign that you are losing a lot of fluid and may be on the road to dehydration. If you’re perspiring heavily, use it as a reminder to replenish by drinking fluids.

Inability to focus is a key indicator that your body is running low on fluids. The brain requires sufficient hydration to run at full capacity, and those who are dehydrated may notice short-term memory lapses and poor levels of concentration and focus.

Bad breath is a little-known, but important sign to take note of. A lack of fluids can prevent your body from making enough saliva, which can cause bacteria growth in the mouth and lead to bad breath.

Food cravings arise for a variety of reasons, but one reason might be dehydration. Dehydration can make it difficult for water-using organs like the liver to produce glycogen, and this can lead to cravings for food.

Conclusion

It’s completely possible to prevent dehydration altogether with good hydration habits. Experts recommend that humans consume about one quart of water per hour of activity, on average – that’s 3.78 liters every four hours. It’s a good idea to get into the habit of taking a drink every 15 minutes, so you’re consistently replenishing the fluids that your body is losing.

No matter how you slice it, dehydration is an issue for everyone. But knowing the signs and symptoms to watch out for is the best place to start.