The kidneys are on either side of the body, just below the rib cage. They are about the size of a fist, bean-shaped, and reddish-brown.
While all organs in our body are important, the kidneys play a crucial role in excreting waste from the blood and maintaining homeostasis within the body.
The issue is that for patients with chronic kidney disease, not only is it important to control salt intake, but the amount of water intake is equally crucial. For healthy individuals, if an excessive amount of water and salt enters the body, it gets expelled through urine or sweat, maintaining a balance within the body. However, for patients with chronic kidney disease, whose kidney function is impaired, excessive water intake can lead to dangerous situations like edema or fluid accumulation in the lungs or heart.
Professor Kim Yang Gyun from the Nephrology Department at Kangdong Kyung Hee University Hospital said, “Quite a few patients with poor kidney function drink too much water. Excessive water intake is not good. The amount of water needed varies from person to person, so it’s best to drink when you’re thirsty.”
According to Kim, the general recommended water intake for a healthy individual is about 1 to 1.5 liters per day, equivalent to about six cups.
Kim advised, “But we also drink water after meals and through other beverages, so there’s not much need to worry about it. Just make sure to drink about 2 to 3 cups.”
Drinking too much water can lead to hyponatremia, a condition where the balance between water and sodium is disrupted.
Kim warned that there are cases where individuals consume 3 to 4 liters of water and suffer from hyponatremia, experiencing symptoms such as dizziness and vomiting. She cautioned against drinking excessive amounts of water to the extent that hospitalization through the emergency room becomes necessary.
Another important point is that beverages like alcohol and coffee should not be considered part of your fluid intake.
Kim explained that while ion beverages are acceptable, coffee and alcohol should not be counted as hydrating fluids. She noted that caffeine can increase diuresis, leading to more significant water loss, and alcohol also dehydrates more than it hydrates. Therefore, there is a need to compensate for this water loss.
Conversely, not drinking enough water can also be problematic, as it can lead to dehydration and potentially damage the kidneys.
Professor Kim Jin Sook from the Nephrology Department at Kyung Hee University Hospital stated, “Patients with kidney disease not only have impaired ability to excrete water and electrolytes but also have reduced ability to excrete potassium. Therefore, they should be cautious about consuming summer fruits like watermelons, melons, and bananas that contain a lot of potassium. If potassium is not excreted efficiently, the concentration of potassium in the blood can increase, leading to muscle weakness, arrhythmia, and in severe cases, cardiac arrest.”
For patients with kidney disease, it’s better to consume small amounts of water and fruits frequently rather than a large amount at once.
“Based on the usual urine output and the degree of kidney function, it’s most important to discuss with a medical specialist and find the appropriate amount of water intake for each individual,” she added.