Electrolyte disorders

The most frequent causes

Prolonged diarrhea and vomiting, heavy sweating, diuretics (which increase loss of potassium and sodium), chronic kidney disease, hormonal disorders (adrenal glands) and heart failure. Some blood pressure medicines can raise potassium, especially when kidney function is reduced (see chronic kidney disease). Drinking large amounts of water with little salt intake, in older people and with some medicines, can lower sodium.

Potassium: what happens when it falls or rises

Potassium maintains the electrical potential of cells. Hypokalemia (low potassium) causes weakness, cramps, constipation and irregular heartbeat. Hyperkalemia (high potassium) often causes no symptoms but can cause dangerous arrhythmia; it is detected on tests and on the ECG. This is why high values need prompt assessment, with an ECG check (palpitations).

Sodium and water

Sodium determines the distribution of water in the body. Hyponatremia (low sodium) causes nausea, headache, confusion and, when severe, seizures. The cause is often an excess of water relative to sodium, not simple salt deficiency, so treatment depends on fluid status. Too rapid correction is dangerous for the nervous system, so it is done gradually with monitoring. Hypernatremia appears mainly with dehydration and great thirst.

What you can do to prevent electrolyte disorders

In most mild cases, electrolyte disorders come from fluid losses or from medicines and are prevented by simple measures. During vomiting, diarrhea, high fever or strong heat, the loss of water and salts requires replacement: oral rehydration solutions, which contain salt and sugar in a suitable ratio, are more effective than plain water alone. In patients with heart or kidney failure, the amount of fluid is set by the doctor, because drinking too much can lower sodium or worsen swelling.

Patients taking diuretics, ACE inhibitors/ARBs (blood pressure medicines), spironolactone or potassium supplements need periodic checks of electrolytes, usually one to two weeks after starting or changing the dose, then every 6 months to a year. Do not use laxatives continuously or drink excessive water without reason. A varied diet with vegetables, fruit, legumes and dairy provides the potassium, magnesium and calcium needed; only in kidney disease or with medicines that raise potassium are some foods (bananas, potatoes, tomatoes, dried fruit) limited, on the doctor’s guidance. Athletes who train long and drink only large amounts of water may develop hyponatremia; in those cases electrolyte drinks are used.

Signs to recognize and what to bring to the visit

Symptoms are often nonspecific: weakness, fatigue, muscle cramps, nausea, headache, confusion, irregular heartbeat, constipation or heavy urination. This is why the diagnosis is made by a test, not by symptoms. Very high or very low potassium can affect the ECG and endanger the rhythm, so an ECG is often done together with the test. Low sodium with confusion or seizures is an emergency.

At the visit bring the full list of medicines and supplements (including diuretics, laxatives, anti-inflammatories and herbal products), earlier tests and a description of the fluids you drink and losses (diarrhea, vomiting, sweating). Useful questions: which electrolyte is disturbed and why; is it related to a medicine; which food should I increase or limit; when should the test be repeated.

Assessment and treatment

Blood tests for electrolytes and creatinine, urine tests and an ECG determine the cause and risk. Treatment targets the cause: adjusting medicines, replacing or restricting fluids, dietary changes, potassium supplements only with medical direction. Do not take potassium supplements or potassium salt substitutes without advice, especially with kidney disease. Severe cases require hospital treatment.

Follow-up takes place every 6 months to a year when there is chronic disease or risky medicines, or sooner when the doctor considers it reasonable and after a change of dose. Care at Tirana Polyclinic: we offer nephrology consultation, ECG and interpretation of tests.