When to see a doctor

By Mayo Clinic Staff

Low potassium typically is detected when you have a blood test due to an illness or the use of diuretics. It is rare for low potassium to cause symptoms if you are feeling well.

Low potassium symptoms include:

  • Weakness.
  • Fatigue.
  • Muscle cramps.
  • Constipation.
  • Irregular heart rhythms, called arrhythmias.

     

Irregular heart rhythms are the most worrisome complication of very low potassium levels, particularly in people who have heart disease.

Talk to your healthcare professional about what your blood test results mean. You may need to change a medicine that's affecting your potassium level. Or you may need to treat another medical condition that's causing your low potassium.

Treatment for low potassium depends on the underlying cause. It may include potassium supplements. Don't start taking potassium supplements without talking to your healthcare professional.

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March 21, 2025

See also

  1. Primary aldosteronism