Hypokalemia – Definition and Causes


Hypokalemia is a condition where the level of potassium in the body is very low, below 3.5 mEq / L. Potassium or potassium are minerals in the body. Nearly 98 percent of potassium is found in cells. Small changes in potassium levels outside the cell can have severe effects on the heart, nerves and muscles.

Potassium is important to maintain some body functions:

  • Muscles need potassium to contract
  • The heart muscle needs potassium to beat properly and regulate blood pressure.

The kidneys are the main organs that control potassium balance by removing excess potassium into the urine.

If potassium levels are low (hypokalemia), you can feel weak because the cellular process is disrupted.

  • The normal potassium level is 3.5-5.0 mEq / L (mEq / L for milliequivalents per liter of blood and this is the unit size used to evaluate electrolyte levels). Low potassium is defined as potassium levels below 3.5 mEq / L.
  • Nearly one in five people hospitalized have low potassium levels.
  • People with eating disorders such as anorexia nervosa and bulimia, patients with AIDS, alcoholics, and those undergoing bariatric surgery have a higher incidence of hypokalemia than others.

Causes of Low Potassium

Low potassium can occur for various reasons. The use of diuretics, diarrhea , and the use of chronic laxatives are the most common causes of low potassium levels.

Diseases and other drugs can also reduce potassium levels. Women and Afro-American races are at high risk of developing hypokalemia.

Other causes of hypokalemia include:

Kidney damage:

  • Certain kidney disorders such as renal tubular acidosis, for example, chronic renal failure and acute renal failure
  • Magnesium deficiency
  • Leukemia
  • Cushing’s disease (and other adrenal disorders)

Potassium loss through the stomach and intestines:

  • Gag
  • excessive use of enemas or laxatives
  • Diarrhea
  • After ileostomy surgery

Drug effects:

  • Water pills (diuretics)
  • Medications used for asthma or emphysema (beta-adrenergic agonist drugs such as bronchodilators, steroids, or theophylline)
  • Aminoglycosides (a type of antibiotics)

Shifting potassium into and out of cells decreases potassium concentration in the blood:

  • Use of insulin
  • Certain metabolic conditions (such as alkalosis)

Reduce food intake or malnutrition:

  • Anorexia
  • Bulimia
  • Bariatric surgery
  • Alcoholism

Usually low potassium symptoms are mild. Sometimes low potassium effects can be unrecognized because they are almost invisible. There may be more than one symptom involving the gastrointestinal (GI), kidney, muscle, heart, and nerve tracts:

  • Weakness, fatigue, or cramping in the muscles of the arms or legs, sometimes severe enough to cause an inability to move the arms or legs due to weakness (similar to paralysis)
  • Tingling or numbness
  • Nausea or vomiting
  • Abdominal cramps and bloating
  • Constipation
  • Palpitations (feeling your heart beating irregularly)
  • Frequent urination or feeling thirsty most of the time
  • Fainting from low blood pressure
  • Abnormal psychological behavior: depression, psychosis, delirium, confusion, or hallucinations.

Low Potassium Diagnosis

Sometimes the cause of low potassium is unclear. Your doctor can perform certain tests to rule out other conditions such as renal tubular acidosis, Cushing’s syndrome , and hypokalemia.

  • If electrolyte imbalance is suspected, a blood test will be performed to check potassium levels, kidney function (BUN and creatinine), glucose, magnesium, calcium, and phosphorus if there is a suspected electrolyte imbalance
  • Because low potassium is known to affect heart rhythms ( arrhythmias ), doctors can recommend checking digoxin levels ( Lanoxin ) if patients use digitalis drugs
  • An antrocardiogram (ECG) or cardiac tracing is performed to detect electrical changes in the heart and some types of irregular heart rhythms that may be caused by low potassium.

Hypokalemia Medical Treatment

If you experience symptoms of low potassium, contact your doctor. If you have muscle cramps, weakness, palpitations, or feel faint and you use diuretics, contact your health professional or go to an emergency care facility or emergency department immediately.

Without symptoms, you will not know you have low potassium levels until you have a routine blood test or an electrocardiogram (ECG, ECG).

Hypokalemia Treatment at Home

If you monitor low potassium levels, avoid long and heavy physical activity because potassium loss occurs with sweating.

If dietary supplements, herbal supplements, diuretics (water pills), or laxatives cause low potassium symptoms, avoid taking this product and consult a doctor. Never stop taking prescription drugs without first consulting your doctor.

Potassium replacement therapy will be directed by the type and severity of the patient’s symptoms. Treatment begins after laboratory tests confirm the diagnosis. People who are suspected of having very low potassium need to have a heart monitor and start infusion.

Usually, those with low potassium levels who are still mild or moderate (2.5-3.5 mEq / L), have no symptoms, or who only have minor complaints only need to be treated with potassium given in the form of pills or liquids. This is preferred because it is easy to give, safe, inexpensive, and easily absorbed from the digestive tract. Some preparations, or doses that are too high, can irritate the stomach and cause vomiting.

If cardiac arrhythmias or symptoms are significant or if potassium levels are less than 2.5 mEq / L, IV potassium (intravenously, via an IV line) must be given. In this situation, the patient needs to be observed in the emergency department. Changing potassium takes several hours because it must be given very slowly intravenously to avoid serious heart problems and avoid irritating blood vessels where the infusion is installed.

Treatment of Hypokalemia

For those with very low potassium, potassium is needed through infusion and potassium taken.


  • If potassium is used with drugs such as ACE inhibitors, there is a risk of elevating potassium levels
  • Potassium-saving diuretics and salts-substitutes that contain potassium can also cause high potassium levels.

Low potassium follow-up
Usually doctors recommend certain doses for potassium supplementation and regulate blood levels taking 2-3 days later.

Doctors may consider switching to potassium-saving diuretics (water pills) if patients need to continue taking diuretics because of other health conditions.

Prevention of Hypokalemia

Changes in diet may be recommended if patients tend to experience low potassium levels. Examples of high potassium foods include:

  • Banana
  • Tomato
  • Orange

Do not use diuretics too often (water pills), and never use other people’s drugs. If the person is on certain medications, ask the doctor how often electrolyte levels need to be checked.

Hypokalemia Prognosis

Low potassium conditions can be treated. Reasons for low potassium must be sought, or most likely will be repeated. With the right therapy, there is usually no further problem.

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