Origin
A potassium deficiency can be caused by a loss of potassium via the kidney into the urine is the most common reason for a potassium deficiency. This can have several causes. In most cases, certain draining drugs (diuretics) are decisive, especially the frequently prescribed loop diuretics (e.g.
furosemide, torasemide) and the group of thiazides (e.g. hydrochlorothiazide / HCT). The body excretes less water-binding sodium due to the drug-induced high fluid losses, but in return excretes more potassium. Potassium losses also occur when taking high-dose penicillins due to similar mechanisms.
Some hormone imbalances also cause potassium loss via the kidneys. The so-called hyperaldosteronism is characterized by excessive concentrations of the hormone aldosterone in the blood. Aldosterone inhibits the excretion of sodium in the kidney in the case of high fluid excretion and excretes potassium as a counterbalance.
An increased blood level therefore leads to a loss of potassium. It can be caused by a benign aldosterone-producing adrenal gland tumor or an enlargement of the adrenal gland (Conn syndrome). A sudden attack of high blood pressure, the displacement of a renal artery and frequent vomiting or diarrhea also cause a pathological increase in aldosterone.
In Cushing’s syndrome the cortisol level in the blood is elevated. Cortisol does not normally affect the electrolyte balance. However, when blood concentrations are too high, it takes over the function of aldosterone, which is structurally very similar.
This mode of action is also possible with drug treatment using cortisone preparations (= inactivated cortisol) and other glucocorticoids. The risk of a potassium deficiency is particularly high when taken together with diuretics. Licorice also causes a higher potassium excretion in a similar way.
- A loss of potassium,
- A disturbance in the redistribution between blood and cell interiors,
- A too low potassium intake is caused.
In addition, certain nutritional states of the body influence the potassium balance of the kidney. Frequent vomiting, poorly controlled diabetes with excess sugar, prolonged starvation or low-protein nutrition and certain diets (e.g.B. Alkaline diet) additionally promote the development of a potassium deficiency.
There are also genetic diseases such as Bartter syndrome and Gittelman syndrome, which cause a potassium deficiency due to their effect on the kidneys. A loss of potassium outside the kidney is most often caused in the intestine by regular diarrhea or ingestion (misuse) of laxatives. Potassium is excreted in a similar way as in the kidney.
A potassium deficiency can also occur in celiac disease. Potassium loss through the skin can occur to a large extent in severe burns, in a mild form when sweating under high temperatures and exertion. Occasionally, a disturbance in the distribution of potassium between the blood and the cell interiors is also the cause of a potassium deficiency.
If the potassium is forced into the cells, the concentration in the blood is subsequently reduced. This is the case when the blood pH value rises sharply (hyperventilation, vomiting), when insulin concentrations in the blood are high (due to insulin administration or acute hyperglycaemia) or when there is a high concentration of stress hormones (adrenaline) in the blood. The latter can be caused by an adrenal gland tumor (pheochromocytoma) or by administration as a drug in the case of slow heartbeat.
Beta-agonists (asthma therapy) and caffeine also cause a redistribution into the cells. Finally, a reduced intake of potassium can also be the trigger. In view of the large amounts of potassium stored in the cells, it takes a long time until the concentration in the blood changes. In addition, the kidney can greatly reduce potassium excretion in the absence of food. Consequently, only severe eating disorders (e.g. anorexia) or alcohol abuse can trigger a potassium deficiency through reduced intake.
