What would happen if you didn’t drink water?

Water is found in abundance all around us, from the moisture in the ground to the icy peaks of mountains, and even within the cells of our own bodies. The average human, depending on factors such as location, body fat percentage, age, and sex, is composed of approximately 55-60% water. Interestingly, newborn babies are even wetter, with a water composition of 75%. However, this percentage decreases to 65% by their first birthday. So, what is the significance of water in our bodies, and how much do we actually need to drink in order to maintain good health?

The H20 within our bodies serves multiple important functions, such as cushioning and lubricating joints, regulating body temperature, and nourishing the brain and spinal cord. It's worth noting that water isn't solely present in our blood. In fact, nearly three quarters of an adult's brain and heart is composed of water, which is roughly equivalent to the moisture content of a banana. Similarly, our lungs contain approximately 83% water, while even seemingly dry bones have a 31% water content. Considering that we are essentially made up of water and surrounded by it, it may seem puzzling as to why we still need to drink an adequate amount. The answer lies in the fact that each day we lose around two to three liters of water through perspiration, urination, bowel movements, and even respiration. While these bodily functions are crucial for our survival, we need to replenish the lost fluids to maintain a balanced water level. Failure to do so can result in dehydration or overhydration, both of which can have serious detrimental effects on our overall health. When our body detects low water levels, sensory receptors in the hypothalamus of the brain signal the release of antidiuretic hormone. This hormone, upon reaching the kidneys, triggers the creation of aquaporins, which are special channels that enable the blood to absorb and retain more water. As a result, urine becomes concentrated and appears darker. Increasing levels of dehydration can lead to noticeable drops in energy, mood, skin moisture, blood pressure, and even cognitive impairment. A dehydrated brain has to work harder to perform the same tasks as a normally hydrated brain, and it may even temporarily shrink due to the lack of water. On the other hand, overhydration, also known as hyponatremia, typically occurs when excessive amounts of water are consumed within a short period of time.

Athletes often fall victim to overhydration due to challenges in maintaining water levels during extreme physical conditions. When the brain is overhydrated, it slows down or even stops the release of antidiuretic hormone into the bloodstream. This dilutes the sodium electrolytes in the body, causing cells to swell. In severe cases, the kidneys may struggle to keep up with the excess diluted urine, leading to water intoxication. Symptoms of water intoxication can include headaches, vomiting, and, in rare instances, seizures or even death. However, it's important to note that this is an extreme situation. For most people with access to clean drinking water, maintaining a well-hydrated system on a day-to-day basis is easily manageable. In the past, it was commonly believed that individuals should consume eight glasses of water per day. However, this estimate has been refined over time. The current consensus is that the necessary amount of water intake largely depends on factors such as body weight and environmental conditions. Recommended daily water intake ranges between 2.5-3.7 liters for men and approximately 2-2.7 liters for women. These ranges may be adjusted based on individual health, activity levels, age, and exposure to heat. While water is the healthiest option for hydration, other beverages, including those containing caffeine like coffee or tea, can also replenish fluids. Additionally, approximately one-fifth of our daily water intake comes from water-rich foods. Fruits and vegetables such as strawberries, cucumbers, and even broccoli contain over 90% water, providing not only hydration but also essential nutrients and fiber. Furthermore, maintaining proper hydration may have various long-term benefits. Studies have indicated that optimal hydration can reduce the risk of stroke, help manage diabetes, and potentially lower the likelihood of certain types of cancer. Regardless, ensuring that you consume an appropriate amount of liquids can have a significant impact on how you feel, think, and function in your day-to-day life.