Potassium is one of the most important minerals in the body. The majority is present in body cells and it is important for a variety of processes such as nerve conduction and muscle function. Potassium is found mainly in fruits, vegetables, potatoes and meat. The potassium balance is maintained by uptake of potassium into the intestine from diet, shifts of potassium over the cell and  excretion into the urine by the kidneys. The kidney, in particular the renal tubules, are most the important factor in maintaining potassium balance. Potassium renal excretion is dependent on many factors. Important factors are the acidity of the blood, the excretion of sodium and the total quantity of urine. A disorder in the excretion of sodium in the renal tubules, therefore, is often accompanied with an impairment of the potassium excretion.

Hypo- and hyperkalemia
Signs and symptoms consistent with a low potassium (hypokalemia) are fatigue, muscle weakness, heart rhythm disturbances, constipation and excessive urination. Patients with a high potassium (hyperkalemia), can present with complaints of the nerves and muscles and develop arrhythmias. Many patients have no symptoms but a significantly abnormal potassium still can lead to sudden cardiac death.

Causes of hpokalemia
A low potassium level in the blood may be caused by too little intake with the diet, inadequate uptake in the intestine, loss through the intestine or shift of potassium into the cell. In addition, potassium may be lost via the urine due to a problem in the kidneys.

Determining the cause
An increase or decrease in potassium excretion in the urine can be determined from blood and urine tests. The latter can be done in a urine sample, ans usually a 24-hour urine sample is collected as well. Depending on the results, further diagnostic tools will be used. This may include specific tests that examine the function of the kidney tubules or genetic research. For a description of specific syndromes which may occur renal hypokalemia, see the links below.

The treatment consists of elimination of the cause, if possible. In addition, we will try to normalize the potassium levels in the blood with drugs

–    Bartter syndrome
–    Gitelman syndrome
–    Renal tubular acidosis
–    Liddle syndrome