K | Potassium

Potassium (K) is the most important intracellular cation, playing a crucial role in maintaining cell functions, muscle (especially heart) contractions, nerve impulse transmission, and the body's water and electrolyte balance. Most of the potassium is within cells, and its serum concentration, although small, is strictly regulated because any deviation can have serious clinical consequences.

The average potassium concentration in the blood is about 4.5 mmol/l. Values from 3.5 to 5.3 mmol/l are considered normal. Increased concentration is called hyperkalemia, and decreased is hypokalemia. Both of these electrolyte imbalances can cause dangerous heart rhythm disturbances and even life-threatening cardiac arrest.

Test principle: Serum potassium concentration is determined by a biochemical method, usually using ion-selective electrodes. Results are given in millimoles per liter (mmol/l).

Recommendations:

• It is recommended for patients with kidney dysfunction, cardiovascular diseases, diabetes, especially those taking insulin or diuretics. The test is also useful for those who are intensely exercising or experiencing heavy physical exertion, as well as those at increased risk of dehydration or suspected electrolyte imbalances.
• Hyperkalemia can be caused by renal failure, tissue breakdown (after injuries or burns), use of certain medications (e.g., ACE inhibitors, potassium-sparing diuretics), adrenal insufficiency, or metabolic acidosis. Hypokalemia is usually caused by excessive fluid loss due to vomiting, diarrhea, sweating, as well as use of diuretics, laxatives, insulin excess, nutritional deficiency, or alcohol consumption.
• Before the test, it is recommended to fast for 8-12 hours. Intensive physical activity should be avoided before the test, as it may temporarily change the potassium concentration in the blood. Test results should be evaluated along with other electrolytes and kidney function indicators.