Blood & Laboratory Values

Potassium – Function & Diseases


As a positively charged ion (cation), potassium is one of the essential minerals and is essential for cell and nerve function.

Action of Potassium

Potassium , together with sodium as an opponent, is one of the most important electrolytes in the human body, which are of crucial importance for maintaining the so-called osmotic pressure in the cells.

Potassium serves as an electrolyte, among other things, to regulate the water balance. Potassium is found almost exclusively inside the cells. The concentration gradient between the inside and outside of the cell is maintained with potassium, as with sodium, on the cell wall with the help of a so-called ion pump (here sodium-potassium pump).

This creates an electrical voltage, which is a prerequisite for the transmission of information between the cells. That is why potassium, together with sodium and calcium, plays an important role in the excitability of nerve and muscle cells, for example those of the heart. The body of an adult contains about 170 g of potassium.


Adults need about 2g of potassium daily. Since the mineral is contained in many foods, a balanced diet usually covers the requirement. The body itself keeps the potassium levels within narrow limits, since rising or falling potassium levels can quickly lead to impulse disturbances in the muscles and nerves, which can then no longer contract properly. 

The hormone aldosterone is responsible for regulating potassium levels. If the potassium level rises, the body releases more of this hormone because it stimulates the kidneys to excrete more potassium.

But potassium is not only important for muscle and nerve functions, it also regulates the fluid balance within the cells. In addition, it plays a role in the production of various proteins , regulates blood pressure and heartbeat and is involved in carbohydrate metabolism and thus in energy production.

Potassium deficiency is usually caused by increased fluid loss. Since the potassium value is strongly linked to the sodium value, an increased intake of sodium automatically leads to a higher excretion of potassium. A high-salt diet can therefore lead to a lack of potassium. Certain medications, such as laxatives and diuretics , can also lead to deficiency. Vomiting and diarrhea , alcoholism , eating disorders such as bulimia and anorexia , certain intestinal diseases and reduced fluid intake also often lead to deficiency symptoms.

Symptoms of this are usually tiredness , reduced performance , cramps , muscle pain , circulatory problems and cardiac arrhythmias . Potassium deficiency can easily be counteracted by changing your diet.

Athletes in particular should make sure they get enough, as they lose more potassium through sweating . Endurance athletes and athletes with intensive training are particularly affected. A deficiency can lead to a serious drop in performance and muscle problems. 

However, the effects of excess potassium are more extreme, since life-threatening cardiac arrhythmias with ventricular fibrillation and death can quickly occur. In bodybuilding in particular, there have already been a number of deaths as a result of taking appropriate preparations that are intended to ensure dehydration before a competition.

Occurrence in food

Foods with a high proportion of potassium are primarily plant-based foods such as fruit and vegetables, grains and nuts. There is a lot of potassium in wheat germ, avocados and bananas in particular. When preparing vegetables, it is important to ensure that potassium is transferred into the water when they are cooked. If this is not used further, the potassium is also lost.

Website | + posts

Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.