In hot summer, people sweat more, and a large amount of sweating can lead to potassium loss; at the same time, the human body in the hot environment, due to the accelerated metabolism, potassium in the plasma can easily be transferred to the cells, thus hypokalemia occurs. Potassium is an indispensable macronutrient in the human body. Its main functions in the human body are to maintain intracellular osmotic pressure and intra- and extracellular acid-base balance to regulate the acid-base balance of body fluids; to participate in the metabolism of carbohydrates and proteins; to maintain neuromuscular excitability and normal function; the concentration of potassium is in close relation with the cardiac muscle’s autonomy, conduction and excitability; in the case of potassium deficiency, the cardiac muscle’s excitability will be elevated; in the opposite case, the excitability will be reduced. decrease, both of which can cause cardiac arrhythmia. Potassium metabolism is characterized by more food and more discharge, less food and less discharge, and no food and no discharge. Therefore, in the hot summer, when the body sweats a lot and the appetite decreases, hypokalemia may be caused by excessive excretion and insufficient intake. What is hypokalemia? Serum potassium (K+) concentration is between 3.5 and 5.5 mmol/L. Usually, serum potassium <3.5 mmol/L is called hypokalemia. When hypokalemia occurs, the nervous system, cardiovascular system, endocrine system, and digestive system, etc., may have corresponding symptoms. For example, weakness of limbs, flaccid paralysis of neuromuscular system of different degrees, especially the lower limbs are the most obvious, which is called potassium deficiency flaccid paralysis. Potassium deficiency can slow down intestinal peristalsis, mild potassium deficiency only lack of appetite, abdominal distension, nausea and constipation, severe potassium deficiency can cause paralytic intestinal obstruction, and even can appear whistle failure, accompanied by cardiovascular system dysfunction, such as chest tightness, palpitations, and even can appear the whistle muscle paralysis, difficulty in whistling, as well as serious cardiac arrhythmia. How to prevent low blood potassium in summer 1, avoid long time outdoor activities, reduce sweating, especially cardiovascular disease, long-term use of diuretics patients, should be regularly rechecked electrolytes, to understand their own blood potassium level; 2, after a lot of sweating, you can drink saline or orange juice and other potassium-containing beverages; 3, more potassium-containing foods, such as bananas, lean pork, peaches, etc.; 4, once the heart panic and chest tightness, weakness of the limbs, cardiac arrhythmia, you should seek medical treatment in time to avoid delaying the condition. Seek medical treatment to avoid delaying the condition.