What are the symptoms of low electrolytes?


Electrolytes or salts are essential substances that are responsible to regulate normal muscle and nerve function, hydrate the body, balance blood pH and pressure and help to repair damaged tissue. Six of the more common electrolytes in the body are sodium, potassium, chloride, calcium, phosphate and bicarbonate. Losing a significant amount of electrolytes through vomiting, diarrhoea, sweating, or burns may be dangerous as it causes symptoms and is potentially fatal. In such cases, patients are required to receive electrolyte imbalance treatment to maintain the normal function of cells and organs. This article highlights the symptoms of low electrolytes of sodium, potassium, chloride, calcium, phosphate and bicarbonate. 

Hyponatremia (low sodium in the blood) happens when the body contains too much water which can dilute the amount of sodium in the blood. Examples of medical illnesses that can cause hyponatremia are heart failure, liver cirrhosis, kidney disease and lung disease. Medications like hydrochlorothiazide and severe blood loss, vomiting or diarrhoea can also result in low sodium in the blood. Hyponatremia due to water intoxication occurs when a person drinks too much water in a short amount of time. If hyponatremia is left untreated, it may result in brain swelling and nerves damage. Symptoms of low sodium are:

  • Nausea and vomiting
  • Headache
  • Difficulty thinking clearly or confused
  • Fatigue, restless or irritable
  • Muscle cramps, spasm or weakness
  • Seizure and fainting

Hypokalemia (low potassium in the blood) is most often caused by significant vomiting or diarrhoea, or diuretic medications like Lasix (furosemide) or hydrochlorothiazide. Patients with hypokalemia may develop serious complications such as irregular heartbeat, disrupted electrical signals that control the heart and impaired the kidneys. Since potassium is mainly in the muscles, the main symptom of hypokalemia is muscle weakness. Initially, the weakness is felt in the legs and then to the trunk, followed by the arms and hands. If hypokalemia is untreated, it can damage the muscles. If the muscles that control the breathing are affected, a person may suffer from difficulty in breathing. The person should visit a doctor.

There are no specific symptoms of signs to hypochloremia (low chloride in the blood). It is usually present with metabolic alkalosis, which is also often asymptomatic. Symptoms directly related to metabolic alkalosis are uncommon. If any, symptoms may be due to loss of volume (dizziness, muscle cramp, fatigue) or hypokalemia. 

Hypocalcemia (low calcium in the blood) can present symptoms ranging from mild to life-threatening. Since calcium is mostly used for muscle contraction, the main symptom of hypocalcemia is tetany, an involuntary contraction of the muscle that indicates neuromuscular irritability. Mild tetany may present with numbness around the mouth, hands and feet or muscle cramps. In severe tetany, patients may have carpopedal spasm (severe painful spasm in the hands and feet), spasm in the larynx or seizures. Other less specific symptoms include fatigue, irritability, anxiety and depression.

A person may develop hypophosphatemia (low phosphate in the blood) due to a number of reasons, such as burns, chronic alcoholism, starvation or medications like diuretics or phosphate binders. Low phosphate for a long time affects the kidneys and bones. While most cases are asymptomatic, patients may have a loss of appetite, muscle weakness and osteomalacia (weakened bones that fracture easily). If left untreated, a serious neuromuscular disturbance may follow such as brain damage, seizure, coma and death. Rhabdomyolysis may also occur in severe phosphate depletion. 

A low level of bicarbonate presents as metabolic acidosis, a serious electrolyte disorder that is characterised by increased acidity in blood pH. The most common causes of chronic metabolic acidosis are diarrhoea, late-stage chronic kidney disease and trauma from road traffic accidents. The symptoms of metabolic acidosis include rapid breathing, confusion, fatigue, headache, loss of appetite, drowsiness and jaundice. Severe metabolic acidosis is harmful and can lead to shock and death.