Recently, the matter of an advanced uremic patient in Xi’an who did not undergo dialysis for 4 days due to sequestration control has received the attention of the general public. Once diagnosed with uremia, it means that the patient’s chronic renal failure has developed to its final stage, when a large amount of kidney tissue has been destroyed and is not renewable. Such patients will not only suffer from uncomfortable symptoms such as vomiting, edema, dizziness, numbness and weakness of limbs, but also threatened by a variety of complications, such as heart failure, lung infection, metabolic acidosis, and even life-threatening. Renal replacement therapy such as hemodialysis or peritoneal dialysis is needed to keep the patient alive. A. Why and how often dialysis is needed for advanced uremia Currently, the recognized treatment methods for advanced uremia are peritoneal dialysis, hemodialysis and kidney transplantation. Among them, hemodialysis is commonly used and the technology has been very mature, is the choice of most uremic patients, can effectively prolong life and ensure the quality of life. As patients with advanced uremia have serious kidney damage, hemodialysis is equivalent to creating “artificial kidneys” for the human body by drawing blood out of the patient’s body through a dialysis machine, removing toxins from it, and then returning it to the body. For conventional hemodialysis, according to the current consensus of “Hemodialysis Mode Selection”, the recommended frequency of treatment is at least 3 times/week, which means that hemodialysis should be performed every 2 days or so, and for patients with unstable hemodynamics, poor cardiovascular function, difficult to control hypertension, high blood phosphorus, etc., the time interval of dialysis should be shortened appropriately as determined by the doctor. Second, what will happen if 4 days without dialysis for patients with advanced uremia, if 4 days without dialysis, may lead to excessive accumulation of metabolic waste in the blood due to severe impairment of kidney function, and water cannot be excreted smoothly, which in turn will cause serious effects on various systems and organs of the body. In addition, electrolyte disorders may occur because excess electrolytes are also not excreted. Patients may develop complications such as water and sodium retention, metabolic acidosis, severe hypertension, heart failure, lung infection, and hyperkalemia, which may manifest as edema, severely elevated blood pressure, nausea, vomiting, dizziness, numbness and weakness of the limbs, as well as chest tightness and difficulty in breathing. In severe cases, it is impossible to eat due to nausea and vomiting, and the respiratory center is suppressed due to severe metabolic acidosis and heart failure, while hyperkalemia can also lead to cardiac arrest, which is life-threatening. Third, how to solve such problems if such diseases exist, you should go to dialysis treatment as soon as possible. If you are in a closed control area, you can contact the control unit, such as the CDC, and wait for the CDC to arrange a vehicle to the relevant hospital for medical treatment.