Potassium makes the heart, muscles and nerves work. Too low a value is harmful, but too high a value too.
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At a glance:
What are the functions of potassium?
Potassium is a mineral and an important electrolyte in the human organism. The metal occurs in the body in dissolved form as a positively charged ion, it is often abbreviated as K. It is involved in many physiological processes in the body together with other electrolytes, especially sodium (Na). With its positive charge, the potassium ion builds up an electrical voltage between the inside of the cell and the cell membrane. This allows signals from nerve cells to be passed on to the muscle cells.
Potassium regulates, among other things, the fluid content and the excitability of the cells. Above all, it plays a crucial role in the functioning of the heart muscle and blood pressure, but the electrolyte also helps regulate the acid-base balance, bone metabolism and insulin production.
When and how does the doctor determine the potassium level?
The heart muscle in particular reacts to fluctuating levels of potassium ions. The potassium level is therefore often measured for the initial diagnosis and control of cardiac arrhythmias, muscle problems such as muscle pain or sensory disorders.
Potassium is excreted via the kidneys and, to a small extent, also via the intestines. Regular monitoring of the potassium level in the blood is therefore also useful for:
severe diarrhea
eating disorder
taking laxatives and diuretics
Kidney disease
deviating values of the other electrolytes (sodium, calcium, magnesium, phosphate)
artificial nutrition
intensive care treatment
The potassium value is determined in the blood serum, in the blood plasma or in the urine (24-hour urine) depending on the diagnostic objective.
Normal values for potassium
The body regulates the potassium content within a very narrow range. The concentration of potassium in the body is mainly controlled by the hormone aldosterone. In an adult human, a potassium level of 3.6 to 5.2 mmol / L (millimoles per liter) is normal. Both a potassium deficiency and an excess of potassium beyond these limits are hazardous to health.
Important to know: laboratories have their own reference values for their investigations. These can differ and must be taken into account when interpreting the blood values.
Potassium Too High? Causes of increased levels in the blood
If the potassium levels are above the normal range, doctors call this hyperkalemia. Values that are too high can have very different causes:
Disruption of kidney function due to acute or chronic kidney weakness or tumors. The kidneys excrete too little potassium.
Medicines: water tablets (diuretics), antibiotics, ACE inhibitors, anti-inflammatory drugs
Acidification of the blood (for example in diabetes)
Hormonal imbalances
Insulin deficiency (in the case of diabetes or malnutrition)
Destruction of cells and / or red blood cells (erythrocytes), for example through injuries, poisons, tumor treatment, hereditary blood diseases
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A healthy body usually compensates for too much potassium in the diet. In these cases, the kidneys excrete the excess potassium with the urine.
False high values can also be caused by an incorrect blood sample. Therefore, if the potassium level is too high, it should be checked by a second blood test.
What to do if the potassium level is too high depends on the cause of the increased value.
Deficiency: causes of low potassium levels
Too low a level of potassium in the blood is called hypokalaemia. A low concentration indicates high fluid loss, such as can occur with diarrhea and vomiting. Long-term use of laxatives also often leads to a potassium deficiency. Drugs that are diuretic can also cause the value to be too low.
Licorice lowers potassium levels
What many do not know: Excessive consumption of liquorice can disrupt the mineral balance of the organism. Certain substances in real licorice influence the release of hormones in the adrenal gland, which in turn stimulate the excretion of potassium and lower its concentration in the blood. This can lead to a potassium deficiency with spikes in blood pressure, heart problems, faintness attacks and water retention.
People with high blood pressure or heart failure, as well as those taking potassium-lowering medication, should therefore limit their consumption of licorice and licorice root products.
Preventing potassium deficiency: covering the daily requirement with food
The body's potassium requirement is around two grams per day. Potassium is consumed through food. To prevent chronic diseases such as high blood pressure, strokes, but also bone loss (osteoporosis), up to 4.7 grams per day is recommended. Foods such as whole grain products, bananas and apricots, mushrooms, beans and cheese have a high potassium content.