What are the symptoms of hypokalemia (low potassium levels)?

From the Guidelines

Low potassium (hypokalemia) can cause various symptoms that range from mild to severe, including muscle weakness, muscle cramps, fatigue, and constipation, and can be defined as K<3.5 mEq/L 1.

Symptoms of Hypokalemia

The symptoms of low potassium can be diverse and affect various aspects of the body. Common symptoms include:

• Muscle weakness
• Muscle cramps
• Fatigue
• Constipation
• Abnormal heart rhythms (arrhythmias), which can feel like palpitations or a racing heartbeat Severe hypokalemia can lead to more serious conditions such as paralysis, respiratory failure, and even life-threatening heart problems. Some people may also experience tingling or numbness, increased urination, excessive thirst, or psychological symptoms like confusion or mood changes.

Importance of Potassium Levels

Potassium is crucial for proper nerve and muscle function, particularly for maintaining normal heart rhythm and muscle contractions. Low levels disrupt the electrical signals that control these functions, leading to the symptoms described. It is essential to maintain serum potassium concentrations in the 4.0 to 5.0 mmol per liter range to prevent the occurrence of either hypokalemia or hyperkalemia, both of which may adversely affect cardiac excitability and conduction and may lead to sudden death 1.

Treatment and Prevention

If you're experiencing symptoms of low potassium, seek medical attention promptly as potassium levels below 2.5 mmol/L are considered dangerous. Treatment typically involves potassium supplements (like potassium chloride tablets) at doses determined by your doctor based on severity. Mild cases might be addressed with potassium-rich foods such as bananas, oranges, potatoes, and spinach. Close observation and follow-up are also crucial in managing hypokalemia, as nonadherence with diet and medications can rapidly and profoundly affect the clinical status of patients 1.

From the Research

Symptoms of Low Potassium

• Low potassium, also known as hypokalemia, can be asymptomatic, but common symptoms include:
  • Cardiac arrhythmias 2, 3, 4
  • Muscle weakness or pain 2, 3, 4
• Severe features of hypokalemia that require urgent treatment include:
  • A serum potassium level of 2.5 mEq per L or less 4
  • Electrocardiography abnormalities 2, 3, 4
  • Neuromuscular symptoms 4
• Hypokalemia can lead to life-threatening cardiac conduction disturbances and neuromuscular dysfunction 3

Causes and Treatment of Low Potassium

• Hypokalemia is caused by decreased intake, renal losses, gastrointestinal losses, or transcellular shifts 4
• Treatment of hypokalemia includes:
  • Oral or intravenous potassium replacement 2, 3, 4
  • Addressing the underlying cause of hypokalemia 4
  • Dietary counseling and adjusting causative medications 4

Comparison with High Potassium

• Hyperkalemia, or high potassium, can also cause cardiac arrhythmias and muscle symptoms 2, 3, 4
• Treatment of hyperkalemia includes:
  • Intravenous calcium, insulin, and inhaled beta agonists 2, 3, 4
  • Hemodialysis in urgent situations 2, 4
  • Potassium binders such as patiromer and sodium zirconium cyclosilicate 4