[Sportschosun reporter Jang Jong-ho] If you have sweated a lot during the hot summer months, staying hydrated is important.
Experts advised that sweat contains not only water but also small amounts of electrolytes such as salt, so it is best to also eat properly.
When water and electrolytes are lost, the body's electrolyte balance is disrupted. In severe cases, dehydration can reduce blood flow to the kidneys and lead to acute kidney injury, a sudden decline in kidney function. This is why electrolyte drinks and sports drinks are often recommended, as they can replenish both water and electrolytes.
Professor Kim Geun-ho of the Department of Nephrology at Ewha Womans University Seoul Hospital said, "During the hot summer months, drinking enough water before you feel thirsty is one of the ways to protect kidney health." He added, "Children, older adults, and patients with chronic conditions such as chronic kidney disease, diabetes, and hypertension, who are more vulnerable to dehydration, should pay even closer attention not only to proper hydration but also to kidney health management."
Dehydration can appear in two forms depending on severity. A lack of body water can cause hypernatremia, while fluid loss accompanied by electrolyte depletion can lead to hypotension and acute kidney injury. In summer, environmental factors play a major role as high temperatures increase sweating and water loss. Children and older adults are especially at risk because their ability to sense thirst is weaker, making dehydration more likely.
Professor Kim explained, "Some of the deaths among older adults from summer heat waves that are reported every year may be related to brain atrophy, a fatal complication of severe hypernatremia." He added, "Other major causes of dehydration include fever, excessive urination, and fluid loss caused by gastrointestinal diseases."
How much water is appropriate to prevent dehydration? The amount can vary depending on age, health condition, and activity level. However, in a resting state without fever or sweating, an appropriate intake is about body weight in kilograms multiplied by 30 milliliters. For a healthy adult, 1.5 to 2 liters a day is considered appropriate, including water obtained from food.
Children, meanwhile, need more water relative to their body weight than adults because they have a larger body surface area and higher calorie consumption.
For patients with chronic kidney disease, however, it is better to maintain the amount of fluid intake recommended by medical staff according to the condition and treatment plan, rather than trying to increase water intake excessively. Older adults also often realize symptoms only after dehydration has progressed significantly, so they need the habit of replenishing fluids regularly before they feel thirsty.
Professor Kim stressed, "If you feel thirsty, you should already take it as a sign that your body is short of water." He added, "Maintaining a balanced nutritional state and replenishing fluids through water-rich fruits and vegetables can also help." He also noted, "Coffee and carbonated drinks that contain a lot of caffeine can cause diuretic effects, so excessive intake should be avoided."
Jang Jong-ho, bellho@sportschosun.com
