The Cause of Dehydration
Dehydration is a common deficiency that most people have experienced at one time or another. Working out in a garage for an hour on a hot summer day will cause a person to sweat and become thirsty. Sweating is the body’s way of cooling itself during strenuous activity and in the process depletes its supply of water which results in thirst. “Your mouth becomes dry because less water is available to make saliva” (Grosvenor and Smolin, 2006). If water is not replenished an individual may become nauseated, light-headed, or dizzy. The reason these symptoms occur is due to the loss of water from sweating, urination, and the body’s inability to store water. Water is also continuously lost through evaporation from the skin and respiratory tract, but how much depends on activity, temperature, humidity, and body size (Grosvenor and Smolin, 2006). All of these factors influence the amount of water a person must consume in order to replenish what is lost through environmental and activity conditions in order to prevent dehydration. According to Grosvenor and Smolin (2006), water is needed more than any other nutrient and men are recommended to consume 3.7 liters a day while women are recommended to consume 2.7 liters a day. Water is needed to maintain health, provide certain functions with the help of electrolytes, and prevent death.
The Body Requires Water
A person must consume water to maintain his or her health because an adult’s body weight is about 60% water (Grosvenor and Smolin, 2006). Over half the body is made up of water, therefore it makes sense to replenish and maintain the body’s main ingredient. “Some water is found inside cells and is known as intracellular fluid and some, referred to as extracellular fluid, is located outside of cells. Extracellular fluid accounts for about a third of total body water and is made up primarily of the water in blood and the fluid between cells, called interstitial fluid; other extracellular fluids include lymph and fluids inside the lumen of the GI tract, the eyes, joints, and spinal chord” (Grosvenor and Smolin, 2006). Water provides the fluid that acts as an environment for communication, transportation, and protection for certain tissues, cells, and organs. The bloodstream, cells, and spaces between cells allow water to pass back and forth through different body compartments when the concentration of dissolved proteins, sodium, potassium, and other small molecules is too high through the process of osmosis (Grosvenor and Smolin, 2006). This movement of water from low-concentrated areas to high-concentrated areas allows the body to move water where it is needed. According to Grosvenor and Smolin (2006), the kidneys regulate how much water is lost depending on the concentration of dissolved particles in the blood; antidiuretic hormone (ADH) may signal the kidneys to reabsorb water to reduce the amount lost in the urine, but alcohol inhibits this hormone causing dehydration. When water passes through different compartments inside the body, it relies on the blood pressure to push water out of the blood and into the spaces between the cells (Grosvenor and Smolin, 2006).
Water Provides Function and Regulates Temperature
The dehydration symptom of thirst caused from insufficient saliva reveals that water generates saliva to make it easier to chew and swallow food (Grosvenor and Smolin, 2006). Without saliva the food we eat would have trouble moving down the gastrointestinal tract. According to Grosvenor and Smolin (2006), water also functions to lubricate the eyes with tears, resist compression to cushion body compartments such as the joints and eyeballs against shock, provide a cushioning effect to protect a fetus in the amniotic sac, deliver oxygen and nutrients to cells and return waste products to the lungs and kidneys for excretion through blood in the body, regulate body temperature, and facilitate chemical reactions. Earlier we discussed that the body produces sweat as a way to cool itself, but the physical property of the time it takes water to slowly change from hot to cold also helps our bodies maintain a regular temperature. The water in the body’s blood plays a more active role by dilating the blood vessels in the skin to allow blood to flow closer to the surface and release heat into the air, giving skin that red appearance seen during a hot day or workout (Grosvenor and Smolin, 2006). The body is normally warm, so once the body’s temperature begins rising it tries to release the body heat in the blood by bringing it closer to the surface of the skin. “In a cold environment the opposite occurs. The blood vessels in the skin constrict, restricting the flow of blood near the surface and conserving body heat” (Grosvenor and Smolin, 2006). Finally, water plays a major role in the chemical reactions that take place inside the body. According to Grosvenor and Smolin (2006), water participates in chemical reactions by providing a solvent for glucose, amino acids, minerals, and many other substances needed by body cells, joining small molecules together and breaking large molecules apart, and maintaining the proper level of acidity in the body.
Sodium, Potassium, and Chloride Electrolytes
A person walking down the sidewalk requires his or her leg muscles to contract with nerve impulses from the brain that provide instruction. “These activities are triggered by the movement of electrically charged ions dissolved in water. These ions conduct an electrical current and are therefore referred to as electrolytes. Sodium, potassium, and chloride are key electrolytes in [the] body” (Grosvenor and Smolin, 2006). These electrolytes work together to create a charge that causes nerves to signal processes inside the body. Sodium is a positively charged extracellular ion that regulates the total amount of water in the body and its movement into and out of cells creates electrical signals that are critical to communication between the brain, nervous system, and muscles (Grosvenor and Smolin, 2006). Potassium is a positively charged ion found inside of cells at very high concentrations that are essential for normal cell function, regulation of the heartbeat, and proper muscle functioning (Grosvenor and Smolin, 2006). Chloride is a negatively charged ion found in conjunction with sodium chloride in table salt when dissolved in water. According to Grosvenor and Smolin (2006), chloride helps maintain fluid levels and inhibit bacterial growth. These core electrolytes are needed to balance the amount of fluid in the body and produce movement by facilitating communication through nerve impulses.
Dehydration is Dangerous
Considering that the human body is mostly made of water and uses charged ions that are dissolved in water to conduct electrical impulses to function, reveals that the body is completely reliant on water to survive. When the body loses enough water to reduce blood volume the ability to transport oxygen and nutrients to cells and excrete waste products becomes compromised (Grosvenor and Smolin, 2006). Most have experienced the usual symptoms of thirst, headache, fatigue, loss of appetite, dark-colored urine and dry mouth from becoming dehydrated. If dehydration continues more severe symptoms, such as nausea, difficulty concentrating, confusion, and disorientation may affect thinking ability and physical performance (Grosvenor and Smolin, 2006). People who are unable to get to water for days will eventually die from dehydration, so consuming water regularly is the most important factor for normal functioning within the body.
Grosvenor, M. B., & Smolin, L. A. (2006). Nutrition: Everyday choices. New Jersey:
John Wiley & Sons, Inc.