Dehydration Effects

Dehydration is the “excessive loss of water resulting in depletion of body fluids” (Grosvenor & Smolin, 2006, p. 282). When the body goes through dehydration there can be many symptoms. Some of these symptoms can include: feelings of nausea, light-headedness, and feeling dizzy. Dehydration can cause symptoms to show more rapidly than any other vitamin deficiency. With other vitamin deficiencies, days or weeks can pass before symptoms are felt by the body (Grosvenor & Smolin, 2006). Symptoms can be seen when dehydrated after only an hour of activity on a hot day. Water is essential to health maintenance because the human body is more than half water. The typical adult’s body weight is about 60% water. This number is even higher in small children and infants. When dehydration sets in, it is important to replace this lost water as fast as possible. Another reason that water is essential to health maintenance is that the body needs a certain proportion of water and dissolved substances. This proportion of water and dissolved substances is necessary so that all the chemical reactions necessary to sustain life continue to function (Grosvenor & Smolin, 2006).
Water has many functions in the body. Muscles are made up of almost 75% water while bones are about 25% water. Water is used as a fluid both inside and outside the cells in a body. Water found in the cells is known as intracellular fluid while water outside the cells is known as extracellular fluid. As a solvent, water is how the body is able to dissolve such necessary substances as: glucose, amino acids, and minerals. Water is used by the body to lubricate and clean internal surfaces. The body also uses water to help cushion certain body parts from the shock of an impact. Body temperature is regulated by water. This is because water can hold heat and water changes temperature slowly. An example of water regulating body temperature is “when body temperature starts to rise, the blood vessels in the skin dilate, causing blood to flow close to the surface where it can release some of the heat to the surrounding air” (Grosvenor & Smolin, 2006, p. 283).
Since the body does not permanently store water it must constantly be replaced. When the body does not obtain the water that it needs dehydration can set in. Any changes in the amount of water in the body can be dangerous and even life-threatening. Water is so important to the human body that it is possible to survive without food for up to eight weeks, but without consuming any water, the human body can only survive a few days. When water levels are too low, there is an effect on the body’s ability to deliver oxygen and nutrients to the cells. Waste removal is also affected when the body does not have enough water. Some of the early symptoms of dehydration include: headache, fatigue, thirst, dry eyes and mouth, and loss of appetite. Some of the later symptoms can include: nausea, confusion, difficulty concentrating, and disorientation (Grosvenor & Smolin, 2006). The most common time for dehydration to occur is during exercise. This is because during exercise the body losses water through sweat.
To help avoid dehydration it is important to drink water on a regular basis. During exercise, it is important to take breaks at regular intervals to replace the water that has been lost because of sweating. The daily recommended amount of water for men is 3.7 liters and 2.7 liters a day for women. This number can be affected by multiple factors. Diet, activity level, and environmental temperature are some of the factors that can change the daily recommended amount of water for people. The minor symptoms of dehydration will go away quickly after replacing the lost water but if left untreated medical attention may be necessary. While it may be difficult to consume too much water, overhydrating can be as dangerous as dehydrating. Water toxicity can be the result of consuming too much water. Some of the early symptoms of water toxicity can be similar to dehydration. Nausea, muscle cramps, disorientation, and confusion are just some of the symptoms of water toxicity. “To help prevent water toxicity it is recommended that beverages containing dilute solutions of sodium as well as sugar, such as sports beverages, be used to replace water losses when exercise continues for more than an hour” (Grosvenor & Smolin, 2006, p. 287). Electrolytes are important because they help maintain acid-base in the body. Electrolytes are “substances that separate in water to form positively and negatively charged ions that conduct an electrical current” (Grosvenor & Smolin, 2006, p. 287). The three key electrolytes in the body are sodium, potassium, and chloride. It is important to control the amount of sodium excreted from the body because sodium helps to regulate blood pressure. If the body loses more sodium than it takes in blood pressure can drop. When this happens the body will release proteins and hormones to help the kidneys retain water and sodium. Renin is an enzyme that is the first substance released in this situation. When renin is released, it starts events that lead to the production of the protein angiotensin II. This protein is used to increase blood pressure in more than one way. First, angiotensin II causes the muscles in blood vessel walls to constrict. Second, this protein causes the body to release the hormone aldosterone. Aldosterone “causes the kidneys to increase sodium reabsorption” (Grosvenor & Smolin, 2006, p. 289). If there is too much sodium in the body blood pressure can start to rise. This increase in blood pressure will inhibit the release of renin and aldosterone. Potassium is another electrolyte used by the body. The movement of potassium and sodium ions creates nerve impulses. There are other functions of potassium in the body. Some of these functions are: positive intracellular ion, nerve transmission, muscle contraction, and fluid balance. Too much potassium in the body can be deadly. When the blood levels of potassium start to rise, the cells in the body begin to take in potassium. This is done to prevent the extracellular fluid levels of potassium from reaching fatal levels. Most people today have a diet high in sodium and low in potassium. This can be helped by eating foods that unprocessed. Some of these unprocessed foods are: fruits, vegetables, whole grains, and fresh meats. All of these foods are high in potassium. Heart failure is just one of the possible outcomes of potassium deficiency. The final electrolyte is chloride. Unlike potassium and sodium, chloride is a negative ion. Chloride is used as a major extracellular ion and for fluid balance. Just like sodium, chloride is used in processed foods. This has led to people having a diet high in chloride. Alcohol can lead to water loss because “alcohol inhibits the activity of ADH” (Grosvenor & Smolin, 2006, p. 284). People suffering from a hangover are experiencing the symptoms of dehydration. Researchers are starting to change their stance on dehydration and caffeine. In the past, it was believed that “caffeinated drinks had a diuretic effect (Zeratsky, 2011). Based on these old beliefs, the diuretic effect brought on by the caffeinated drinks could cause dehydration because the body would need to urinate more than normal after drinking them. New research has shown that this is not true however and that the diuretic effect only becomes an issue when caffeine is consumed in large quantities a day (Zeratsky, 2011). Knowing the causes of dehydration is helpful so the symptoms of dehydration can be avoided. Staying hydrated during exercise is important because of the water lost to sweating. When the body starts to show the initial symptoms of dehydration it is important to take measures to prevent the symptoms from going further. Regulation of the diet is also necessary to make sure the proportion of water and dissolved substances in the body is maintained. Following these simple rules can help prevent dehydration and the serious symptoms associated with it.
References
Grosvenor, M. B., & Smolin, L. A. (2006). Nutrition: Everyday Choices. Hoboken, NJ: John Wiley & Sons.

Zeratsky, K. (2011). Nutrition and healthy eating. Retrieved from http://www.mayoclinic.com/health/caffeinated-drinks/AN01661