Low potassium level

  • Definition
    • Low potassium level is a condition in which the amount of potassium in the blood is lower than normal. The medical name of this condition is hypokalemia.

  • Alternative Names
    • Potassium - low; Low blood potassium; Hypokalemia

  • Causes
    • Potassium is needed for cells to function properly. You get potassium through food. The kidneys remove excess potassium through the urinary system to keep a proper balance of the mineral in the body.

      Common causes of low potassium level include:

      • Antibiotics
      • Diarrhea or vomiting
      • Using too much laxative, which can cause diarrhea
      • Chronic kidney disease
      • Diuretic medicines (water pills), used to treat heart failure and high blood pressure
      • Eating disorders (such as bulimia)
      • Low magnesium level
      • Sweating
  • Symptoms
    • A small drop in potassium level often does not cause symptoms, which may be mild, and may include:

      • Constipation
      • Feeling of skipped heart beats or palpitations
      • Fatigue
      • Muscle damage
      • Muscle weakness or spasms
      • Tingling or numbness

      A large drop in potassium level may lead to abnormal heart rhythms, especially in people with heart disease. This can cause you to feel lightheaded or faint. A very low potassium level can even cause your heart to stop.

  • Exams and Tests
  • Treatment
    • If your condition is mild, your provider will likely prescribe oral potassium pills. If your condition is severe, you may need to get potassium through a vein (IV).

      If you need diuretics, your provider may:

      • Switch you to a form that keeps potassium in the body. This type of diuretic is called potassium-sparing.
      • Prescribe extra potassium for you to take every day.

      Eating foods rich in potassium can help treat and prevent low level of potassium. These foods include:

      • Avocados
      • Baked potato
      • Bananas
      • Bran
      • Carrots
      • Cooked lean beef
      • Milk
      • Oranges
      • Peanut butter
      • Peas and beans
      • Salmon
      • Seaweed
      • Spinach
      • Tomatoes
      • Wheat germ
  • Outlook (Prognosis)
    • Taking potassium supplements can usually correct the problem. In severe cases, without proper treatment, a severe drop in potassium level can lead to serious heart rhythm problems that can be fatal.

  • Possible Complications
    • In severe cases, life-threatening paralysis may develop. This is more common when there is too much thyroid hormone in the blood. This is called thyrotoxic periodic paralysis.

  • When to Contact a Medical Professional
    • Call your provider right away if you have been vomiting or have had excessive diarrhea, or if you are taking diuretics and have symptoms of hypokalemia.

  • References
    • Mount DB, Zandi-Nejad K. Disorders of potassium balance. In: Taal MW, Chertow GM, Marsden PA, et al, eds. Brenner and Rector's The Kidney. 9th ed. Philadelphia, PA: Elsevier Saunders; 2012:chap 17.

      Seifter JL. Potassium disorders. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 117.