Excessive potassium excretion is commonly associated with long-term use of diuretics or excessive dosage. Long-term use of thiazide diuretics may lead to water and electrolyte disturbances, resulting in hyponatremia, hypochlorhydria and hypokalemia. The kidneys are extremely capable of excreting potassium quickly, and about 90% of ingested potassium is excreted in the urine within 4 hours. It is excreted in the form of Na+-K+ exchange in the renal tubular epithelium. The characteristics of potassium excretion are more excretion by eating more, less excretion by eating less, and also excretion by not eating, i.e. the kidney’s ability to conserve potassium is lower than its ability to conserve sodium. So, what tests should be done for excessive kidney potassium excretion? The following are the examination items for excessive potassium excretion by kidney: 1. Blood laboratory indicators Decrease in serum potassium concentration, L, blood pH at normal high limit or >7.45, sodium ion concentration at normal low limit or <135mmol/L. 2. Urine laboratory indicators Decrease in urinary potassium concentration, acidic urinary pH, high urinary sodium excretion. 3.Electrocardiographic examination The earliest manifestation is ST segment depression, T wave depression, widening, inversion, appearance of δ wave, Q-T time prolongation, the above changes can be improved after potassium supplementation. For patients with excessive potassium excretion, especially those who are fasting, they should be supplied with sugar and liquid by infusion, and if they have urine, they should be supplemented with potassium in time.