[Sportschosun reporter Jang Jong-ho] Summer dehydration is more than simple thirst. It means the body's fluid and electrolyte balance has broken down, and it can lead to serious complications such as heatstroke and kidney failure. Older adults, especially those with limited mobility or impaired cognitive function, are at even greater risk because they may have difficulty drinking water on their own.
According to data from the Health Insurance Review & Assessment Service (HIRA) over the past three years, a total of 76,886 patients received medical care for acute kidney injury between June and August from 2023 to 2025. The share of older adults was particularly high. In 2024, people aged 60 and older accounted for about 76.58% of all patients, while those aged 80 and above made up about 31.31%.
Looking at the figures by year, patients treated between June and August accounted for about 27.97% of the annual total in 2023 and 27.55% in 2024. The higher share in summer than in other seasons shows that kidney health requires especially careful management during periods of dehydration and heat exposure.
Older adults are especially vulnerable to summer dehydration and acute kidney injury because of age-related changes in the body. As people age, total body water decreases, the kidneys' ability to concentrate urine declines, and their capacity to maintain kidney function during dehydration also weakens.
Their ability to sense thirst also becomes less sensitive, so they may not feel thirsty enough even when the body lacks water. For those with limited mobility or impaired cognitive function, the risk rises further because they may struggle to drink water on their own.
The problem is that when dehydration occurs, blood volume falls and blood flow to the kidneys also decreases. Because the kidneys filter waste from the blood by receiving sufficient blood flow, reduced circulation can sharply impair kidney function and lead to acute kidney injury.
Patients with underlying conditions such as diabetes, high blood pressure, chronic kidney disease, or heart failure are especially vulnerable to dehydration-related kidney damage, and even mild dehydration can worsen kidney function. The risk of acute kidney injury can also rise when people take nonsteroidal anti-inflammatory drugs, diuretics, or continue certain blood pressure medications while dehydrated. If symptoms such as vomiting, diarrhea, or fever are present, or if it is difficult to eat and drink enough, patients should not keep taking their usual medications as before. Instead, they should consult medical staff about whether their prescriptions need to be adjusted.
Acute kidney injury can often be reversed with prompt treatment such as fluid therapy if it is detected early. However, if treatment is delayed or the damage is severe, recovery may be incomplete and the condition can progress to chronic kidney disease. In severe cases, dialysis may be needed, which makes early response crucial.
Professor Cha Jin-ju of the nephrology department at Korea University Hospital said, "If dehydration from extreme heat is added to reduced kidney function caused by aging, it can lead to acute kidney injury." She added, "Even if older adults do not feel thirsty, it is better to drink water at regular intervals rather than consuming a large amount at once."
She also stressed, "If urine output drops noticeably compared with usual, if urine becomes unusually dark, or if symptoms such as dizziness, fatigue, loss of appetite, swelling, or shortness of breath appear, do not assume it is just the heat. Visit a medical institution and have kidney function and electrolyte levels checked."
However, it is not appropriate to recommend that everyone simply increase fluid intake. Professor Cha said, "For patients who need to restrict fluid intake because of heart failure, advanced chronic kidney disease, or dialysis treatment, drinking too much water can worsen swelling or shortness of breath." She added, "These patients should consult medical staff to determine an appropriate amount of fluid intake based on their condition and urine output." She also said, "In summer, older adults who may have difficulty recognizing dehydration need active attention and careful observation from family members and people around them."
Jang Jong-ho, bellho@sportschosun.com
This article has been translated by GripLabs Mingo AI.
