Hypokalemia, is a medical condition that occurs when an individual has a lower than normal potassium level in their bloodstream. For a healthy individual, the blood potassium level should be 3.6 to around 5.2 millimoles per liter.

Getting low potassium levels such as 2.5mmol/L or below can be very dangerous. When a person gets these low levels, they should get medical attention immediately. [1,2]

What is potassium and Its Uses?

The human body has several electrolytes that are crucial for cell function, and potassium is actually one of them. Potassium electrolytes are concentrated in the cells of the body, and they play a very important role. In the human body, only two percent of the total potassium is found in the blood stream.Any changes in the blood stream levels of potassium can greatly affect the functioning of the human body.

Potassium has a great role of maintaining the electrical activities in the body cells. The body cells that have high electrical activity such as the nerves and muscles like the heart are seriously affected then the potassium levels in the body fall. [2,4]

the potassium levels in the body fall image

Causes of low potassium in the body

Many people believe that low potassium is commonly caused by poor dietary intake. However, this is not true. The most common causes of hypokalemia is the loss of potassium from the gastrointestinal tract or from the kidney. Potassium levels in the body can fall from the GI tract due to the following reasons.

  • Diarrhea.
  • Vomiting
  • Ileostomy. Some patients who have had conditions that forced them to have a bowel surgery and get an
  • ileostomy. Their stool output might sometimes contain huge amounts of potassium.
  • The use of laxative has also been linked to low potassium levels for some patients.
  • Villous adenoma is type of colon polyp, and it is said to cause hypokalemia in patients too. The polyp causes the patients colon to leak some amount of potassium. [4,7,9,10]

Potassium can be lost from the kidney due to the following reasons.

  • Some diuretic medications, such as Hydrochlorothiazide and furosemide can cause the levels of potassium to fall.
  • When the levels of corticosteroids are elevated, the potassium levels go down. This can be caused by the use of medications such as prednisone or by some illnesses such as Cushing’s syndrome.
  • Elevated levels of aldosterone in the body can also lead to hypokalemia. Aldosterone is a hormone in the human body that increases due to renal artery stenosis or due to adrenal tumors.
  • When the magnesium levels in the body are low, the levels of potassium go down too.
  • Renal tubular acidosis also causes hypokalemia.

Hypokalemia can also be caused by the effects of the following medications.

  • Prednisone.
  • Aminoglycosides such as gentamicin or tobramycin
  • Amphotericin B [4,10]

Symptoms of Hypokalemia

Potassium is an important element in the body. Potassium greatly affects the manner your neuromuscular cells discharge energy and also how they regenerate this energy so that they can be able to fire again. When your potassium levels are low, these cells are not able to repolarize and most of the time, they cannot fire repeatedly as expected. When this happens, your muscles and nerves cannot function as usual, and the patient gets some symptoms.

Most of the time, the symptoms of this condition are mild. However, they can sometimes be vague. A patient might get one or more symptoms involving the GI, muscles, kidneys, nerves and the heart. Here are some of the most common symptoms

  • Some patients experience tiredness, weakness or even cramping in their legs or arm muscles. These cramping might be severe sometimes, causing the patient not to be unable to move their legs or arms.
  • Numbness or tingling is also common.
  • Vomiting and a lot of nausea might also be present.
  • Bloating and abdominal cramping.
  • Constipation.
  • Some patients complain about palpitations.
  • Feeling thirsty all the time and passing large amounts of urine.
  • Due to low blood pressure, some patients experience fainting.
  • Changes in psychological behavior in the patient. Some might get depression, delirium, psychosis, confusion or even hallucinations. [1,5]

How is low potassium diagnosed? (with ECG (EKG) changes)

It is very easy to measure your potassium levels during your normal routine blood tests. Hypokalemia is considered a potential complication when an individual is taking some medications. Patients who suffer from high blood pressure are mostly given some diuretics like hydrochlorothiazide or Lasix. This means that they have a high risk of getting hypokalemia, so their potassium levels should be monitored closely.

If you have a patient who is ill, it is important to be extremely careful if they are vomiting or have diarrhea. These might lead to dehydration and weakness, common symptoms of hypokalemia. These patients should have their electrolyte levels monitored just to be sure that the potassium levels are good or whether they need to be replaced.

Difference between Normal ECG and Hypokalemia picture

Difference between Normal ECG and Hypokalemia

There are some EKG or ECG changes that are mostly associated with hypokalemia. Sometimes, the diagnosis of hypokalemia is done by getting the U waves in the EKG tracing. When the condition is serious, there can be severe disturbances in the heart rhythm. [1,6,8]

Prominent U waves in Hypokalemia ECG Also check Hyperkalemia ECG image

Prominent U waves in Hypokalemia ECG Also check Hyperkalemia ECG

Treatment and Management of low potassium

Patients who have serum potassium levels of above 3.0 mEq/liter have nothing to worry about. These levels are not considered to be dangerous, and they can be given potassium replacements by mouth.However, patients with potassium levels that are lower than 3.0mEq/liter might require some intravenous replacement, depending on their current medical condition and symptoms. Most of the time, the decision is patient –specific, and it depends on the diagnosis, the patient’s ability to tolerate fluid and the medication by mouth and the circumstances of the illnesses.

If the low potassium levels are short term or caused by self -limited diseases such as vomiting, diarrhea or gastroenteritis, the patients does not have to worry about medications. This is because the potassium levels can restore on their own. If the hypokalemia is severe, or may be the doctor predicts that the potassium losses will be on going, potassium supplementation or replacement is very important.For individuals who get hypokalemia due to the use of diuretics, the doctor might recommend a small amount of oral potassium.

This is due to the fact that the loss will continue as long as the diuretic is being used. The oral potassium supplementation is presented in liquid or in pill form. The dosages of these supplements are measured using mEg. The common dosage is 10-20mEq daily.Patients suffering from hypokalemia can also consume foods that are high in potassium.

This is always the first option given by the doctor to replace potassium, especially if the condition is not serious. Oranges, bananas, apricots and tomatoes are some of the food that are considered to be high in potassium content.

Potassium is extracted through the kidneys, and most of the time, the doctor will order blood tests that will monitor the patients kidney function. This way, it will be easier to monitor and predict the potassium levels from getting too high.

If a patient will be getting their potassium supplements intravenously, the doctor should give it slowly. Potassium is very irritating to the veins, and it should only be given at a maximum rate of 10mEq. Infusing potassium too fast in the veins can easily cause heart irritations and gradually promote potentially dangerous rhythms like ventricular tachycardia. [5,9]

A Special Situation: Periodic Paralysis

Although very rare, sometimes the potassium levels in the body moves from the blood stream in to the cells of the body. When this happens, the serum potassium levels drops to 1.0 mEq/liter or sometimes lower. This can be very serious to the patient. The muscles become very week to a point where the patient cannot move their body and become paralyzed. The most affected parts are the legs and arms. The breathing and swallowing muscles are also affected sometimes.

Periodic paralysis is said to be hereditary and sometimes, it might be precipitated by excessive exercising, consuming high carbohydrate or too salty meals, or even occur without any cause. People who get periodic paralysis can be treated easy. They should be given potassium replacement intravenously. The recovery is expected to take place within the first 24 hours. [3,5]

Prevention of low potassium

The human body is able to maintain its potassium levels in the normal ranges as long as an individual takes foods that are rich in potassium. When an individual gets any short time illnesses that can make the body to loose potassium levels, the body can easily compensate the loss.

If the doctor says that the loss of the potassium is ongoing, it is crucial for a patient and the health care provider to anticipate this loss, and urgently consider the routine potassium replacement that will work effectively. Leaving the condition untreated can lead to serious problems. [4,6]


  1. Diseases & Conditions – Medscape Reference [Internet]. Emedicine.medscape.com. 2016 [cited 2 May 2016]. Available from: http://emedicine.medscape.com
  2. Mayo Clinic [Internet]. Mayoclinic.org. 2016 [cited 2 May 2016]. Available from: http://www.mayoclinic.org
  3. National Library of Medicine – National Institutes of Health [Internet]. Nlm.nih.gov. 2016 [cited 2 May 2016]. Available from: https://www.nlm.nih.gov
  4. Marjorie Lazoff M, Cadogan M, Morgenstern J, Long N, Long N, Lynch D et al. LITFL: Life in the Fast Lane Medical Blog [Internet]. LITFL: Life in the Fast Lane Medical Blog. 2016 [cited 2 May 2016]. Available from: http://lifeinthefastlane.com
  5. The MSD Manuals – Trusted Medical Information [Internet]. Msdmanuals.com. 2016 [cited 2 May 2016]. Available from: http://www.msdmanuals.com
  6. [Internet]. 2016 [cited 2 May 2016]. Available from: http://Electrolyte Disorders
  7. The MSD Manuals – Trusted Medical Information [Internet]. Msdmanuals.com. 2016 [cited 2 May 2016]. Available from: http://www.msdmanuals.com
  8. Medical Information & Trusted Health Advice: Healthline [Internet]. Healthline.com. 2016 [cited 2 May 2016]. Available from: http://www.healthline.com
  9. [Internet]. Emedicinehealth.com. 2016 [cited 2 May 2016]. Available from: http://www.emedicinehealth.com
  10. [Internet]. 2016 [cited 2 May 2016]. Available from: http://healthy living az list
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Published on by under Diseases and Conditions.
Article was last reviewed on September 26th, 2017.

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