Water is an essential chemical substance in the human body, and it possesses unique physical and chemical properties. The human body consists of 45% to 77% water depending on age and sex. Water plays a significant role in the nourishment of the cells and removal of waste from the human body and its deficiency may lead to poor metabolism and functioning of the body (Brown, 2011). The excessive loss of water or deficiency of body water is referred to as dehydration. In dehydration, the body’s output of water is greater than the intake, and it can be attributed to a plethora of facets; reduced fluid intake, excessive heat and sweating, vomiting, diarrhea, inappropriate use of diuretics-substances that increase fluid loss through increased urination-, gastrointestinal suction, and hemorrhage. In tandem with this, an increase in concentration of sodium or disturbance of certain electrolytes like potassium may amount to dehydration. Similarly, some diseases such as diabetes-both insipidus and mellitus-and Addison’s disease may result to dehydration (Rosdahl & Kowalski, 2008).
Importance of water
Water is a fundamental requirement for normal and better functioning of the body. The core importance of water includes; defense against disease through the removal of toxic substances that may cause headache and fatigue upon their accumulation (Evans, 2006). Further, it helps in reducing the risk of cancer related to the digestive systems; bladder cancer and colon cancer, through dilution of cancer-causing agents. Similarly, it moistens the mucous lining in sinus passages, thence preventing nose bleeding, sinusitis and allergies. It also moistens the mucous lining in the lungs (bronchi and nasal passages), preventing the irritation of the lungs, and consequently making them resistant to viruses and bacteria. In light with this, water also aids in metabolism and fluid retention of the body. Water also assists in the proper maintenance of muscle tone and offers adequate contraction and relaxation of the muscles. It also prevents the sagging of the skin (Evans, 2006). In addition to this, water is also essential in losing weight, in reference to its ability to flush out all the by-products of fat break down. It also helps in digestion, prevention of constipation and creation of healthful moods.
Function of water
For effective functioning, water is distributed in variable proportions all over the body; the brain consists of 90% of the water, 83% composition of blood is made up of water, muscles and bones consist of 75% and 22% of water respectively. Water transports nutrients in food to the body cells. Further, the essential metabolites; vitamins, minerals, glucose, amino acids and enzymes, also dissolve in water and transported to the body cell (Bio Fact sheet, 1998). Similarly, large molecules of proteins are also transported in water in the form of colloids (Brown, 2011). Water also offers an ideal environment for a chemical reaction, attributed to its thermal stability and exceptional solvent properties. Enzyme reactions, respiration and excretion also occur in solution. In some reactions, water acts as a reactant, for instance in the hydrolytic reactions, in the digestive systems (Bio Fact sheet, 1998).
Water also acts as a temperature regulator ascribed to its high specific heat capacity. Heat regulation and the need to maintain a constant body temperature are essential in endothermic organism, since it aids in the optimization of enzyme activity and the regulation of metabolism activity, as well (Rosdahl & Kowalski, 2008). Water also plays a vital role in support of the body, and it is achieved through the filling of skeletal tissues with water. In conjunction to this, water has a significant function in reproduction. The growth of foetus develops in the womb, a water filled sac that dispenses thermal and physical stability (Bio Fact sheet, 1998).
Effects of dehydration
The initial symptoms of dehydration are; thirst, accompanied by frequent drinking of more fluids or water, dark urine with a strong odour, dry coughs, sneezing, headaches, depressions, nosebleeds, acne and dry skin. The severity of dehydration increases when the intake of fluid cannot sustain the fluid loss from the body (Rosdahl & Kowalski, 2008). When the situation is not corrected, it amounts to the drying and malfunctioning of the body tissues, diminishing physical performance. It can also lead to mental confusion, since the brain cells are susceptible to dehydration. Untreated, the condition can advance to a coma (Rosdahl & Kowalski, 2008). Dehydration can also cause severe damage to some of the body organs; kidneys and liver. This is ascribed to low-blood pressure caused by reduced blood volume in circulation. Other common problems associated with dehydration include; heat exhaustion, urinary tract infections, constipation, salivary gland function problems and the development of kidney stones.
Function of electrolytes
Sodium, potassium and chloride ions are among the essential electrolytes within the body that aid in the metabolism. The principal-food sources of sodium ion (Na +) is table salt, meat, dairy foods, eggs, inclusive of processed and preserved foods like bacon. The key functions of the ion are to maintain an appropriate body fluid balance, achieved through maintenance of osmotic pressure, assist in the normal functioning of neurons and muscle cells, and help in maintaining an acid-base balance in the body system (Rosdahl & Kowalski, 2008). On the other hand, dry fruits, nuts, vegetables and meat are the prime-food source of potassium ions (K+). Similar to sodium ions, they maintain body fluid balance through osmotic pressure, assist in functioning of neurons and muscle cells, and maintain acid-balance of the body system (Rosdahl & Kowalski, 2008). Chloride ion (Cl-) is anion obtained from milk, milk products and fish. It is also essential in the maintenance of body fluid and acid-base balance. Unlike sodium and potassium ion, it maintains the low pH of the gastric juice in the stomach, purposefully for digestion process (Rosdahl & Kowalski, 2008).
Effects of Alcohol and Caffeine on Dehydration
Alcohol and caffeine are diuretic substances, and when consumed in excess, they increase the rate of water loss through increased urination. Similarly, they inhibit the production of antidiuretic hormone (ADH) also referred as vasopressin, which stimulates the re-absorption of water in the kidneys (Insel, Ross, McMahon & Bernstein, 2011). The excess water lost through urination is less concentrated and this results to a higher concentration of ions in the blood stream. To rebuff this, the water in the cells moves to the blood stream through osmosis, across the concentration gradient. The cells remain with less water, hence, dehydration (Insel et al, 2011).
Ways of preventing dehydration
The first response of the body to dehydration is the reduction of urine output of the kidney and decreased sweating. In line with this, the water moves from the intracellular fluid section in to the intravascular fluids to maintain a stable water balance. However, the effective way of preventing dehydration is through the administration of electrolytes and supplement fluids, which can aid in the correction of the condition (Rosdahl & Kowalski, 2008). Drinking of 6 to 8 glasses of water daily helps in the retention of body fluid balance. In light with this, avoiding: excess alcohol, consumption of drinks with caffeine and intake of salty foods after exercise, may contribute to the reduction levels of dehydration (Insel et al, 2011). Drinking of water before, during and after increased activity or exercise is a requisite in the recovery of lost fluid through sweating. In cases of diarrhea, vomiting and fever, it becomes necessary to increase the intake of fluids.
In passing, water plays a notable role in metabolism and functioning of the body system. It provides an efficient medium for the delivery of nutrients in the cells, and removal of waste products from the cells. Nevertheless, the lack of enough water in the body is the mainspring of dehydration. Severe effects of dehydration can emanate to drying of body tissues, chronic infections, malfunctioning of the body, diminished physical and mental function and consequently death. Subsequently, the intake of adequate fluids and electrolytes, avoidance of excess alcohol and consumption of drinks with caffeine, can aid in the prevention of dehydration.
Bio Fact Sheet (1998). The Biological Importance of Water. Retrieved from [http://vle.havant.ac.uk/Biology_web/Biofactsheets/30%20water%20page%201.pdf]
Brown, E. J. (2011). Nutrition Now. Belmont, CA: Wadsworth, Cengage Learning.
Evans, J. (2006). Importance of Water. Retrieved from [http://www.justineevans.co.uk/files/the_importance_of_water.pdf]
Insel et al. (2011). Nutrition (4th ed.). Sudbury, MA: Jones and Barlett Publishers, LLC.
Rosdahl, B. C. & Kowalski, T. M. (2008). Textbook of Basic Nursing (9th ed.). Philadelphia, PA: Lippincott Williams & Wilkins.