What Happens to Your Body When You're Dehydrated?

It’s no surprise that hydration is one of the foundations of a healthy, functioning body. From our brains to our muscles, every system needs fluids in order to carry nutrients, remove bacteria from the body and more. Hydration is key to maintaining overall health. In essence, we need water to survive. Without it, our cells, organs and joints experience distress, leading to a variety of risk factors and consequences.

While sleep, proper nutrition, movement and rest are pillars of holistic wellness, water is equally important. Up to 60 percent of the human body is water. It helps us maintain temperature, digest food and remove waste. As we go about our days, we lose water (through breathing, sweating, etc.), so rehydrating via fluids and water-rich foods is imperative. Not drinking enough water can lead to unwanted repercussions, so I find that keeping a water bottle by my side makes it easier to consistently sip on fluids throughout the day.

Signs and Symptoms of Dehydration

Even slight dehydration can produce an array of symptoms: tiredness, headaches, increased hunger and low blood pressure. In essence, dehydration occurs when you are taking in fewer fluids than the body is losing. In other words, when those lost fluids aren’t replaced, the body isn’t able to carry out its normal functions. Especially during exercise, as well as in hotter climates and warmer months, it’s important to be proactive. As body temperature increases, so does the need for fluids.

Fortunately, the body is quick to indicate when it’s low on water. One of the easiest ways to determine this is via your tongue. In many cases, it will feel dry or sticky when you’re dehydrated. Additionally, check the color of your urine. When urine is light in color (i.e. a pale yellow), you are likely drinking enough water. However, if the color is dark yellow, you may be dehydrated. Dehydration can also cause constipation. After all, fluids are necessary in order to digest food and help excrete waste from the body. Sluggishness, headaches and nausea may indicate a lack of fluids. Medical research demonstrates that not drinking enough water can cause you to remain tired even after a full night of rest.

Risk Factors

Dehydration is correlated to fainting, rapid heart beat and poor brain function. When the body is deficient in fluids, blood volume and blood pressure lower, leading to lightheadedness (or potentially fainting) after suddenly standing up. The heart must work harder to supply blood to the body. Typically, a faster heartbeat and quicker breath are signs of your heart working harder to function efficiently. Given that the brain is more than 70 percent water, it should not be surprising that dehydration can impair cognitive performance, including alertness and memory. 

Staying Hydrated

To ward off dehydration, aim for approximately eight 8-ounce glasses of water per day. For pure and high-quality mineral water, Primus not only hydrates the body, but it also contains naturally occurring minerals to maintain health on a micro level. In addition to drinking plain or sparkling water, other sources of hydration include soups and stews, smoothies, low-sugar veggie (or fruit) juices and water-rich produce. From grapefruit and watermelon to cucumbers, bell peppers and celery, it’s possible to increase your fluids from food as well.

When it comes to staying hydrated, I also enjoy adding fresh herbs, veggies and fruit to plain, filtered water. For example, combining lemon, cucumber and mint is very refreshing, as well as chopped strawberries and basil. You can even add a pinch of high-quality sea salt for electrolytes (promoting proper absorption) or chia seeds for satiation and fiber.


Written by Edie Horstman

Edie Horstman is a certified Integrative Nutrition Health Coach, wellness blogger, and freelance writer. She works with health-focused brands, co-creating content in the digital marketing space. She lives in Denver, Colorado.


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  2. https://www.healthline.com/health/how-to-tell-if-youre-dehydrated#14-symptoms
  3. https://www.heart.org/en/health-topics/high-blood-pressure/the-facts-about-high-blood-pressure/low-blood-pressure-when-blood-pressure-is-too-low
  4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2908954/
  5. https://www.healthline.com/health/how-to-tell-if-youre-dehydrated#14-symptoms