Fatal Risks from Potassium and Phosphorus Intake
Hemodialysis Patients Must Exercise Special Caution
Mrs. A, a housewife in her 60s living in Buk-gu, Ulsan, has decided to stop making kimchi this year, a tradition she has kept every year.
This is because her husband recently began receiving dialysis treatment for chronic kidney disease. Although her husband used to love kimchi made with fresh oysters, he has decided to give it up this year for the sake of his health. In addition, Mrs. A will not be preparing red bean porridge, which her husband used to enjoy most during the winter solstice.
The reason Mrs. A has given up making kimchi and red bean porridge for her husband is that the potassium and phosphorus contained in these foods can be dangerous for patients undergoing hemodialysis.
For hemodialysis patients, the potassium found in fresh kimchi and oysters, which are commonly enjoyed in winter, can cause hyperkalemia. This may lead to muscle weakness and arrhythmia, and in severe cases, can result in cardiac arrest and loss of life.
Fruits and vegetables also contain high levels of potassium, so caution is needed when consuming them. It is recommended to soak vegetables in water for more than two hours before eating, and to limit fruit intake to a set daily amount. Therefore, patients who have started hemodialysis must always check the ingredients of foods before consuming them. If symptoms such as shortness of breath or chest pain appear due to hyperkalemia or other causes, they should immediately seek emergency hemodialysis or emergency coronary intervention at the nearest hospital.
Red bean porridge, which is traditionally eaten on the winter solstice in Korea, should also be consumed with caution. Red beans contain a high level of phosphorus, and unlike potassium, which is partially filtered out during dialysis, phosphorus is not effectively removed by dialysis. The accumulation of phosphorus in the blood, known as hyperphosphatemia, can cause itching, joint pain, edema, and osteodystrophy. While phosphorus is present in small amounts in almost all foods, those particularly high in phosphorus include dairy products such as cheese, milk, and ice cream, as well as whole grains like brown rice, black rice, pine nuts, and walnuts.
As of 2025, it is estimated that about 130,000 people in Korea are receiving hemodialysis. The number of dialysis patients is rapidly increasing due to the growing number of people with chronic diseases such as diabetes and hypertension, as well as an aging population leading to more cases of chronic kidney disease. Chronic kidney disease is difficult to detect early because symptoms rarely appear until kidney function is almost completely lost. Therefore, the number of hemodialysis patients in Korea is expected to rise sharply in the future.
Kidney disease, also known as renal failure, is a condition in which kidney function is continuously impaired for more than three months. There are usually no symptoms in the early stages, but as function declines, edema, fatigue, and shortness of breath may develop.
Chronic diseases such as diabetes and hypertension are known to be the main causes. Treatment requires managing the underlying disease, taking medication, controlling diet and weight, and improving lifestyle habits such as exercise. In end-stage cases where lifestyle changes are insufficient, hemodialysis or kidney transplantation is necessary.
Hemodialysis is a renal replacement therapy for end-stage kidney disease patients whose kidney function has fallen below 15%. Since their kidneys can no longer adequately remove waste and excess fluids, blood is filtered outside the body using a special tube and artificial device, and then returned to the body. Dialysis helps maintain electrolyte balance and removes excess fluid from the body. Each session of hemodialysis takes more than four hours, and because waste is removed from the blood in a short period, patients often experience sudden fatigue and weakness after treatment.
The most important aspect of care for dialysis patients is dietary management. Dietary guidelines for chronic kidney disease patients vary according to their condition and any accompanying diseases, but generally involve reducing intake of potassium, phosphorus, protein, and sodium, while ensuring adequate intake of carbohydrates and fats to provide and maintain appropriate energy levels.
If patients with chronic kidney disease strictly follow dietary guidelines, they can delay the need to start dialysis and prevent complications such as uremia caused by nitrogenous waste, edema, hypertension, and electrolyte imbalances.
Jung Kyungmin, Director of the Artificial Kidney Center at Ulsan Elijah Hospital, emphasizes, "For hemodialysis patients, it is important to consume nutrients accurately according to prescribed dietary guidelines. Changing eating habits is not easy, so not only the patient's own willpower but also continuous interest and support from family and those around them are necessary."
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