What Are the Causes of Low Magnesium & Potassium?

Low potassium and magnesium levels can be caused by diuretics and some medications.
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Maintaining proper potassium and magnesium levels is essential because they contribute to many basic bodily functions such as heart, muscle and nerve function, as well as digestive health. Potassium and magnesium deficiency can be caused by diuretics, excessive alcohol use and certain medications.



Low potassium and magnesium levels can be caused by diuretics and some medications, as well as excessive alcohol use, intestinal ailments and a variety of other health conditions.

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Low Potassium Causes

Potassium is an electrolyte that is an important part of keeping your muscles, nerves and heart working well. It is also important for digestive and bone health.

Electrolytes are minerals in your blood and other body fluids that carry an electric charge. Normal levels of potassium range from 3.5 mmol/L to 5.1 mmol/L in adults, according to the Cleveland Clinic. Usually, levels under 2.5 mmol/L are considered to be very serious.

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The most common cause of low potassium, or hypokalemia, is excessive potassium loss through urination due to prescription medications that increase urination. Also known as water pills, or diuretics, these types of medications are often prescribed for people who have high blood pressure or heart disease. Low potassium levels are sometimes caused by insufficient potassium in the diet.

Other causes of potassium loss include:


  • Excessive alcohol use
  • Chronic kidney disease
  • Diabetic ketoacidosis
  • Diarrhea
  • Excessive laxative use
  • Excessive sweating
  • Folic acid deficiency
  • Primary aldosteronism
  • Some antibiotic use
  • Vomiting

Mild cases of low potassium might not cause symptoms, but more severe cases might exhibit themselves via muscle twitches, muscle cramps or weakness, muscle paralysis, abnormal heart rhythms and kidney problems.


Low Magnesium Causes

Magnesium, a mineral, is essential to many functions in the body, including the metabolism — the physical and chemical processes in the body that convert and use energy. Every organ in the body, especially the heart, muscles, and kidneys, needs magnesium. Magnesium also contributes to the makeup of teeth and bones.

Low magnesium levels in the blood, or hypomagnesemia, exhibits through symptoms including abnormal eye movements, convulsions, fatigue, muscle spasms or cramps, muscle weakness and numbness. The normal range for magnesium is 1.3 to 2.1 mEq/L (0.65 to 1.05 mmol/L).


The Cleveland Clinic notes that one of the first visible symptoms of lowered magnesium is fatigue. Muscle spasms, weakness or stiffness, loss of appetite and nausea are other common symptoms in the early stages of depletion, although you may not notice any symptoms at first.

Causes of magnesium loss include:


  • Excessive alcohol use
  • Burns that affect a large area of the body
  • Chronic diarrhea
  • Excessive urination (polyuria), such as in uncontrolled diabetes and during recovery from acute kidney failure
  • High blood calcium level (hypercalcemia)
  • Hyperaldosteronism (a disorder in which the adrenal gland releases too much of the hormone aldosterone into the blood)
  • Malabsorption syndromes, such as celiac disease and inflammatory bowel disease
  • Malnutrition
  • Medicines including amphotericin, cisplatin, cyclosporine, diuretics, proton pump inhibitors and aminoglycoside antibiotics
  • Sweating


Read more:Difference Between Magnesium and Manganese

Low Potassium and Magnesium Treatment

Low potassium levels are diagnosed with a blood test. Potassium supplements are typically prescribed if you have low potassium levels. If the situation is severe, potassium might be given as an intravenous solution. If an underlying condition exists that causes the hypokalemia, such as excessive urination or an overactive thyroid, it must also be treated.


The recommended daily allowance for potassium is 4,700 mg. Food sources are the best way to keep potassium levels at their desired amount. These include apricots, bananas, beans, beef, broccoli, chicken, fish, lentils, milk, nuts, fresh spinach, tomatoes and zucchini, among many other fruits and vegetables.

If you suspect your magnesium level is low, your doctor will prescribe a blood test. Depending on the results, you may have to take a magnesium supplement until you are back to normal.


The recommended daily allowance for magnesium intake is 400 mg. To maintain healthy magnesium levels, get your daily amount through food sources. Choose green leafy vegetables such as spinach, as well as avocados, bananas, tofu, legumes, nuts, seeds and whole grains. Magnesium is also added to some breakfast cereals and other fortified foods. Tap, mineral and bottled waters can also be sources of magnesium, but the amount of magnesium in water varies by source and brand.




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