Potassium is one of the most important elements in the cells of our body. Its normal intracellular concentration is 100-150 mEq/L, and its extracellular concentration is 3.5-5 mEq/L. 98% of the total potassium in the human body is found inside the cells. Especially skeletal muscles carry 70-75% of total body K+.

One of the vital elements in the blood, potassium, K

Potassium is one of the most important elements in the cells of our body. Its normal intracellular concentration is 100-150 mEq/L, and its extracellular concentration is 3.5-5 mEq/L. 98% of the total potassium in the human body is found inside the cells. Especially skeletal muscles carry 70-75% of total body K+. In addition, liver, erythrocytes and bones are tissues rich in potassium. High K concentration in the cell is necessary for the continuation of normal cell functions such as cell metabolism and growth, cell division, nerve transmission, muscle function, optimal enzyme function, DNA synthesis, volume regulation and acid-base balance.

The amount of potassium taken in the diet is approximately 80 mEq/day (50-150 mEq). Foods high in potassium are oranges, grapes, potatoes, bananas, avocados and raisins. Potassium can switch between intracellular and extracellular environments within minutes depending on many factors in the body. Most of the excess potassium (90%) is excreted by the kidneys.



A blood potassium test is done to determine if the blood potassium concentration is within normal limits and to help evaluate electrolyte imbalance. Excess potassium is called hyperkalemia, and low is called hypokalemia. A blood potassium test can be performed in kidney or heart disease, hypertension, or any suspected disorder of blood electrolytes.

Potassium values are examined in patients who are thought to have problems in the acid-base balance in the body. Losses due to excessive excretion of potassium or accumulations due to its inability to excrete it are of vital value. Conditions such as heavy exercise that cause the potassium in the cell to pass into the blood can also cause blood potassium values to increase.

The main regulating hormone of potassium in body stores is aldosterone. This hormone maintains potassium balance in the body by affecting potassium excretion mainly in kidney distal tubular cells. The body also has a control system for aldosterone. Aldosterone synthesis is increased in hyperkalemia and decreased in hypokalemia.

Hypokalemia/hypokalaemia:

Hypokalemia is a blood plasma K+ level below 3.5 mEq/L. However, most patients are asymptomatic until the plasma K+ drops below 3 mEq/L.



A decrease in blood potassium level in less than 12 hours is called acute hypokalemia. In general, alkalosis, which is a disorder of acid-base balance in the body, insulin therapy or treatment with β2-agonist drugs can cause low blood potassium.

A low blood potassium level that develops for more than 24 hours is called chronic hypokalemia.

Symptoms such as palpitations, muscle weakness, cramps, paralysis, paresthesia, constipation, nausea, vomiting, abdominal cramps, polyuria, nocturia, polydipsia, psychosis, delirium, hallucinations, and depression may be seen in patients with hypokalemia.

Hypokalemia is not evaluated alone, but together with the clinical findings and tests of other possible causes.

Causes of low blood potassium (K+) (Hypopotashemia / hypokalemia):

  • Penetration of potassium from the blood plasma into the cell
    • Acute alkalosis (respiratory, metabolic)
    • Giving insulin
    • Beta-adrenergic activity
    • Hypokalemic periodic paralysis
    • Barium poisoning
    • Hypothermia
    • Rapid increase in blood cells
    • Thyrotoxicosis
    • During the treatment of megaloblastic anemias
  • Insufficient potassium intake
  • Gastrointestinal losses
    • Loss of stomach
      • Vomiting
      • Nasogastric drainage
      • Pyloric stenosis
    • Loss from the gut
      • Diarrhea
      • Villous adenoma
      • Chronic laxative use
      • Biliary drainage
      • Ureterosigmoidostomy
      • Overuse of laxatives
    • Excessive sweating
    • Severe burns
    • Kidney loss
      • Mineralocorticoid increase
      • Leukemias
      • Primary hyperaldosteronism
      • Cushing’s syndrome
      • Primary adrenal disease
      • Corticosteroid use
      • Nonendocrine tumors
      • Congenital adrenal hyperplasia
      • 11 beta-hydroxylase deficiency
      • 17 alpha-hydroxylase deficiency
      • Liddle syndrome
      • Bartter and Gitelman syndrome
      • Diuretic use
      • Renal tubular acidosis
      • Interstitial nephritis
      • Postobstructive diuresis
      • Chewing tobacco
    • Other
      • Hypomagnesemia
      • Malnutrition
      • TPN usage
      • Vitamin D intoxication
      • Heavy exercises
      • Heart attack
      • Medicines
        • Amphotericin B
        • Cisplatin
        • Theophylline
        • Corticosteroids
        • Mineralcorticoids
        • Alkali-stimulated alkalose laxatives
        • Osmotic diuretics
        • Gentamicin
        • Sympathomimetics
        • Insulin
        • Carbenoxolone
        • Tetracycline
        • Vitamin B12

Hyperkalemia/hyperkalemia:

Hyperkalemia is the measurement of blood plasma potassium level above 5.5 mEq/L. Hyperkalemia rarely occurs because the kidneys have too much potassium excretion capacity. However, if there are kidney diseases, it may be difficult to remove excess potassium.



Symptoms of hyperkalemia are rare and are usually discovered incidentally. Potassium elevation can be observed in the expected tables in known patients. Symptoms such as fatigue, muscle weakness, motor losses, paresthesia, paralysis, hypoventilation, respiratory muscle paralysis, abdominal distension and diarrhea may be seen in patients with kiperpotassemia. Depending on other accompanying diseases, the clinic may become much more severe.

Cardiac symptoms may worsen and be life-threatening in patients with a K+ value of 7.5 mEq/L and above. Any level of hyperkalemia exceeding 6 mEq/L should be treated as it can be life-threatening.

Muscle symptoms may not be seen until the K+ value rises above 8 mEq/L. Since blood plasma potassium levels may not be directly proportional to symptoms, it may be necessary to evaluate kidney functions, blood gases, aldosterone levels, blood glucose and calcium levels, insulin levels, and many other tests.

Causes of hyperkalemia / hyperkalemia:

  • Excessive potassium intake
    • Oral potassium salts and excessive dietary potassium intake
    • Potassium and salt supplement therapy
    • High-dose potassium-penicillin
    • Addition of excess potassium to parenteral fluids
    • Pending, excessive blood transfusion
  • Potassium out of the cell
    • Tumor lysis
    • Rhabdomyolysis
    • Hemolysis
    • Internal hemorrhage
    • Trauma
    • Surgical
    • Burn
    • Shock
    • Sepsis
    • Metabolic acidosis
    • Lack of insulin
    • Extreme exercise
    • Hyperosmolarity
    • Medicines
      • ACE inhibitors
      • Cyclosporine
      • Amiloride
      • Cytotoxics
      • Digoxin toxicity
      • Citrated blood transfusion
      • Heparin
      • Spironolactone
      • Medicines containing K+
      • Succinyl choline
      • Beta-Blockers
      • Alpha agonists
      • Lithium
      • Triamterene
      • NSAID
      • Trimethoprim
      • Pentamidine
      • Arginine hydrochloride
    • Familial hyperkalemic periodic paralysis
  • Decreased renal potassium excretion
    • Acute kidney failure
    • End-stage renal disease
    • Decreased mineralocorticoid activity
    • Tubular secretion defect: Renal Tubular Acidosis II and IV
  • Hypoaldosteronism
  • Pseudohypoaldosteronism (resistance to aldosterone in organs)
    • SLE
    • Sickle cell anemia
    • Obstructive uropathy
    • Transplantation
    • Use of potassium-sparing diuretics
  • Sodium channel blockade
    • Use of potassium-sparing diuretics
    • Trimethoprim
    • Pentamidine



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