Importance of blood for electrolytes
The blood is the main transport route for electrolytes. Every cell in the body is reached via the blood vessels and small capillaries. The blood collects the electrolytes that we have ingested through food or liquid in the intestines and distributes them throughout the body where they are needed.
The kidney is the filter that decides via various regulatory mechanisms which electrolytes are still needed in the body and which can be excreted via the urine. By determining the electrolytes in a blood sample, it is possible to find out how the body’s balance is. Many diseases can be read very well from the electrolyte values.
The most important in diagnostics are sodium, potassium and calcium. They are largely controlled by hormones. They are the most sensitive, get out of balance the fastest and have the most serious consequences.
Sodium and potassium are controlled by the hormone aldosterone (a so-called mineral corticoid), which is secreted from the adrenal cortex, while calcium is controlled by the parathyroid hormone from the parathyroid gland. Both hormones give their signals to the kidney as to whether the electrolytes should be excreted in excess or retained in the body in the event of a deficiency. However, if there are disturbances in this control circuit, e.g. due to certain drugs, diseases of the hormone glands or deterioration of the kidney function, the electrolyte balance shifts, which becomes noticeable in the body.
Deficiency and consequences
Not only a lack, but also a shift in the balance of electrolytes or an excess of a certain electrolyte can have serious consequences, depending on its extent. A lack of sodium manifests itself through drowsiness, confusion and also nausea. If, on the other hand, there is an excess of sodium in the blood, seizures comparable to epileptic seizures can occur and can even lead to coma.
Changes in potassium levels are most noticeable in the heart. If you have less than 3.6 mmol/l potassium, e.g. due to certain medications such as diuretics (“water tablets”), constipation, muscle weakness with a decrease in reflexes, paraesthesia and numbness of the skin may occur. If you have more than 5.2 mmol/l, the reflexes are rather increased, but temporary paralysis can also occur.
However, the most important consequence of a potassium deficiency or excess is cardiac arrhythmia. Potassium is essential for the transmission of signals to the heart. If this balance is disturbed, ventricular fibrillation can even occur!
Calcium is also important for the heart, but heart rhythm disturbances do not occur as frequently with excess calcium as with potassium. If one has too much calcium, this is particularly noticeable through nausea and vomiting, kidney stones, bone pain and muscle weakness. Too little calcium manifests itself by tingling on the skin, especially on the face, and muscle cramps in the hands and feet (so-called tetany with paw position).
Too little magnesium is symptomatically similar to calcium deficiency, e.g. with muscle cramps, but neurological symptoms such as delirium or temporary heart failure can also occur. Too much magnesium often does not manifest itself at all, possibly leading to drowsiness. Chloride ions play hardly any role in diagnostics, as they are regulated by sodium.
If an imbalance occurs, sodium is also affected, which becomes primarily symptomatic. Bicarbonate plays a role mainly in the acid-base balance, whereby the bicarbonate takes over the function of the base. A deficiency occurs, for example, in diarrhea diseases when the body loses a lot of bicarbonate.
The result is an overacidification of the body, which can be partly compensated by counterregulation. Serious consequences hardly ever occur. One should be careful with the arbitrary refilling of electrolytes.
Often the symptoms are very unspecific and cannot necessarily be attributed to an electrolyte disorder without checking the blood values. If, for example, a severe electrolyte disorder is noticed during a stay in the clinic, this can be compensated by infusions or medication. However, replenishing electrolytes yourself is recommended in one situation in particular, namely diarrhoea.
In this case, one often loses a lot of electrolytes due to frequent visits to the toilet or even vomiting. To replenish these electrolytes, ready-to-use electrolyte solutions in powder form can be purchased in pharmacies.They are excellent for restoring the electrolyte balance, and often you feel much better after taking them. So-called isotonic drinks can also be very useful during competitive sports with high water loss during sweating. You can also prevent electrolyte shifts with the corresponding consequences by avoiding foods that contain a lot of potassium, such as bananas or dried fruits, for example, if you are a kidney patient.
