Potassium Deficiency May Affect Your Muscles & Your Heart

Muscle cramps, muscle spasms, and cardiac arrhythmias can be common potassium deficiency symptoms. Here is what you need to know.

A bunch of bananas that contain potassium

One banana contains 422 milligrams of potassium.

© Zhanghaobeibei | Dreamstime

Some of the most direct and severe potassium deficiency symptoms are painful muscle cramps and spasms, muscle weakness, and heartbeat irregularities. These increases or decreases in heart rate can be especially damaging in cases where other heart problems also exist, and the muscle cramps can be debilitating when they occur during strenuous exercise. If you are experiencing these symptoms, a trip to the doctor is in order. But fortunately, it usually just takes a nutritious diet to avoid these potassium deficiency symptoms.

Potassium and Muscles

Muscle cells and the neuron cells that cause them to flex (contract) are especially reliant on steady potassium levels. Potassium ensures that electrical signals are not sent to the muscles too rapidly. Spasms and cramps can result from potassium deficiency because the muscles receive too many signals to contract and are not given enough time to relax. This can cause muscles to contract in a constant, painful, uncontrolled manner.

The Heart is Also a Muscle – How Does Potassium Affect the Heart?

Cardiac muscle is also sensitive to potassium deficiency. Although muscle cells in the heart respond much more slowly to electrical signals and are less susceptible to spasms, they will still contract more easily than normal when potassium is deficient. This can cause the heart to beat in an abnormal rhythm, a condition called arrhythmia.

Arrhythmia induced by low potassium is prevalent in heart failure patients due to the regular use of diuretics and other therapies. A symptom of arrhythmia can be either an increase or a decrease in heart rate.

How to Improve Potassium Deficiency Symptoms

According to the National Institutes of Health, the average daily recommended amounts of potassium vary based on age and sex.

Recommended Daily Amount of Potassium
Age Male Female
Birth to 6 months 400 mg 400 mg
7–12 months 860 mg 860 mg
1–3 years 2,000 mg 2,000 mg
4–8 years 2,300 mg 2,300 mg
9–13 years 2,500 mg 2,300 mg
14–18 years 3,000 mg 2,300 mg
19+ years 3,400 mg 2,600 mg

Potassium is found naturally in many foods, to an effective way to solve potassium deficiency is a balanced diet with potassium-rich foods. If a change in diet still results in potassium deficiency symptoms, a doctor may recommend a potassium supplement to achieve the proper daily recommended amount.

One study found that just two servings of bananas can increase blood potassium by 4.4% after one hour! Other potassium-rich foods include:

  • Apricots
  • Squash
  • Raisins
  • Salmon
  • Spinach

Many common health conditions may be the result of nutritional deficiencies. Learn more about serotonin deficiency, GABA deficiency, magnesium deficiency, and deficiencies that cause fatigue.


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UHN Staff

University Health News is produced by the award-winning editors and authors of Belvoir Media Group’s Health & Wellness Division. Headquartered in Norwalk, Conn., with editorial offices in Florida, Cleveland, Pittsburgh, … Read More

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