Our bodies need water to function properly like a vehicle needs fuel. Just as a vehicle cannot run without refuelling, our body cannot function when it loses more fluids than it takes in and we experience dehydration. The body loses water and electrolytes “through a variety of outlets, such as perspiration, excretion, tears, and even our saliva,” says Dr Mahmud Kara, founder of KaraMD, Ohio, USA. The body needs key electrolytes like calcium, chloride, magnesium, and phosphorus to function properly.
A closer look at cellular activity
“Dehydration reduces cell permeability (the ability of a molecule to pass in and out of the cell), hindering nutrient absorption, biochemical reactions, and waste removal in our bodies,” says Dr Soumita, chief nutritionist, at Aster RV Hospital, Bengaluru.
Apparent signs of dehydration
While feeling thirsty is often a sign that the body needs more fluids, it may come as a surprise that one can be dehydrated without experiencing thirst. This lesser-known fact highlights the importance of drinking water regularly and staying hydrated, even when one does not feel thirsty.
Dr Kara and Dr Soumita outline the common signs of dehydration alongside its underlying causes.
- Darker than usual urine indicating that the body is retaining water to compensate for dehydration.
- Bad breath and dry mouth – because dehydration reduces saliva, lowers mouth pH, and increases odour-causing bacteria.
- Low energy, fatigue, and weakness. Dehydration can decrease blood volume, making it harder for the heart to pump oxygen and nutrients to the muscles and organs.
- Dizziness, light-headedness, and headaches, caused by a lack of blood flow to the brain.
- Muscle cramps that occur when electrolytes become imbalanced due to dehydration.
- Dry skin, which can be a result of the body’s decreased ability to maintain proper fluid levels in the skin.
- Loss of strength that can result from imbalanced electrolytes.
- Loss of appetite or food cravings that may differ from person to person.
- Chills resulting from the body’s inability to regulate its internal temperature due to dehydration.
- Constipation when the body tries to retain water in the intestines.
Link between dehydration and cognitive function
In a 2011 study published in the Journal of Nutrition, researcher Matthew S Ganio found that dehydration gave rise to negative mood, impaired concentration, and headaches. The individuals in the study were seen to have decreased visual vigilance and memory, fatigue, and anxiety due to dehydration. A 2019 study by researcher Na Zhang published in the National Library of Medicine records similar results: negative effect on mood and cognitive performance, especially visual and brain function.
Zhang notes that water makes up to 75 per cent of the brain mass. Moreover, water is also required to transport oxygen within the body. As such, water is crucial for health. A 2005 study published in Biological Psychology by researcher Harris R Lieberman found that soldiers who lost 10-15 per cent of their body weight due to dehydration during military training exercises experienced symptoms of dizziness, fainting, and confusion. In extreme cases, severe dehydration can lead to heat stroke, organ failure, and death.
The consequences of chronic dehydration
Dr Kara emphasises that “proper balance of water and electrolytes is necessary for many important functions in the body.” A 2022 study by researcher Kory Taylor published in the National Library of Medicine shows that chronic dehydration can increase the risk of heart and lung disease and may even shorten one’s lifespan.
Proper intake of water and electrolytes is essential to keep the nerves, cells and organs of the cardiovascular system functioning properly, explains Dr Kara. “If this does not happen it could lead to issues with blood pressure and heart rhythm,” he adds.
Severe performance decrements along with increase in body temperature and respiratory rates may be observed when a fluid deficit of 4 per cent or more occurs, observes Dr Soumita. “Dehydration that causes a loss of 10 per cent or more of body weight can be fatal.”
Chronic dehydration can increase the risk of urinary tract infection (UTI). Moreover, “kidney failure is a common occurrence. Although it is reversible if it is due to dehydration and is treated early,” says Dr Soumita.
David Mason, a certified personal trainer and licensed speed, agility, and quickness coach and the founder of Barbells Abroad, based in Sheridan, UK adds some other perils of chronic dehydration. They are:
- Reduced kidney function and kidney stones
- Constipation
- Hypovolemic shock – a life-threatening condition where low blood volume causes a drop in blood pressure
- Fits, seizures, and brain damage
Steps to hydration
Here are some preventive measures provided by Dr Soumita and Dr Sara Encisco, a primary care physician at Mercy Personal Physicians at Lutherville, Maryland.
- Drink plenty of fluids and eat foods high in water such as fruits and vegetables. People facing vomiting and diarrhoea need to take in more fluids.
- Always have water with you. Having a reusable, refillable bottle is a great way to remind one to drink water throughout the day.
- Avoid sugary beverages like sodas as they do not hydrate and often end up replacing water.
Water is an athlete’s best friend
Mason says water plays a paramount role in an athlete’s world or anyone who exercises regularly. “Water aids in weight management and improves focus while exercising. Adding electrolytes in the water is an added advantage.”
