Low Potassium: Symptoms and Causes

Potassium is an essential mineral that regulates various critical physiological functions, including cellular metabolism, heart and muscle function, and nerve impulse transmission. 

Low potassium levels, also known as hypokalemia, can lead to arrhythmia, muscle weakness, poor sleep quality, and dysregulated moods. 

Discover common low potassium symptoms and learn how to manage and reduce the risk of potassium deficiency. 

7 low potassium symptoms

Lack of potassium is one of the most common electrolyte deficiencies. 

Depending on the level of deficiency, symptoms can be vague or more severe, and cases of extremely low potassium can lead to respiratory failure, paralysis, and kidney damage.

Here are seven symptoms of low blood potassium concentrations.

1. Insomnia

Those deficient in potassium may have difficulty falling and staying asleep due to muscle tightness, unease, or excessive thinking. 

Potassium promotes restful sleep by relaxing the muscles associated with conditions such as restless legs syndrome, which typically occurs at night. This essential mineral may also help regulate stress hormones, including cortisol and adrenaline, inducing feelings of calmness and relaxation.

A study published in Sleep found that potassium supplements shortened the time it takes to fall asleep and improved sleep quality in patients following a low-potassium diet.

2. High blood pressure

Lack of adequate potassium has been shown to worsen high blood pressure in those with hypertension. 

This is likely due to the relationship between sodium and potassium, which normalizes blood pressure when balanced. 

When potassium levels are low, sodium retention increases, leading to higher blood volume and, consequently, elevated blood pressure. An elevated sodium-to-potassium ratio in the body is also linked to increased arterial stiffness, heart disease, aortic aneurysms, and other cardiovascular problems.  

Fortunately, increasing potassium intake can negate the adverse effects of sodium, which helps promote healthy blood pressure and cardiovascular health. 

3. Muscle cramps and weakness

Muscle cramps or significant muscle weakness, especially after sweating or exercise, can indicate electrolyte imbalances and potassium deficiency. 

Electrolytes, including potassium, magnesium, and sodium, help muscles contract and relax, and maintaining balanced electrolyte levels is crucial to reducing the risk of muscle cramps. 

Though optimal potassium levels can help with muscle recovery and normal muscle function, too much potassium may also lead to muscle cramps, twitching, and spasms. 

Research published in Case Reports in Neurological Medicine found that excessive potassium intake has been linked to nocturnal muscle cramps.

4. Constipation

Potassium deficiency may lead to constipation, as potassium helps regulate optimal muscle function, including those in the digestive tract. 

A deficiency can prevent the smooth muscles in the intestines from contracting properly. This can slow down digestion and the movement of waste within the large intestines, which is linked to bloating and constipation.

5. Poor blood sugar control 

Insulin-resistant individuals and diabetics who take insulin injections to manage elevated blood sugar levels are commonly deficient in potassium. 

Insulin is a hormone that regulates blood potassium levels by stimulating its cellular uptake. Individuals with poor blood sugar control typically release large amounts of insulin, which can cause hyperinsulinemia and dangerously lower potassium levels.

“Insulin plays a critical role in potassium balance. This leaves people with diabetes, metabolic syndrome, and obesity and those following a high-carb diet at risk of potassium deficiency,” explains Dr. Berg. 

6. Anxiety

Depression and anxiety commonly co-exist, and there may be a link between mood irregularities and low potassium levels. It has been suggested this may be due to potassium’s ability to increase serotonin concentrations in the brain. 

Serotonin is a neurotransmitter that regulates moods and feelings of happiness. Many antidepressants and anti-anxiety medications help increase serotonin levels in brain cells to treat symptoms.

A study published in The British Journal of Nutrition found that a diet high in electrolytes, including potassium, effectively improved depression and tension over four weeks.

7. Abnormal heart rhythms

Potassium is essential for regulating heartbeats as it facilitates electrical signal transmission in cardiac tissue. This explains why a low blood potassium level can cause abnormal heart rhythms, such as palpitations, characterized by feeling your heartbeat fluttering, racing, or skipping beats. 

Research published in Cureus found that “Hypokalemia can present with various patterns of arrhythmia such as premature ventricular complexes, atrial fibrillation, atrial flutter, supraventricular tachycardia, and, in the worst cases, ventricular fibrillation, which can be life-threatening.”

Watch the video below to learn more about the causes and symptoms of low potassium.

Causes of low potassium 

Potassium deficiency is becoming more prevalent and is on the rise, primarily because many people don’t consume enough of this essential mineral.

According to the National Institutes of Health (NIH), the recommended daily value (DV) of potassium for adults is 4,700 milligrams (mg) per day. However, the average American adult consumes only around 500 mg daily. 

A study published in the Journal of the American College of Nutrition found that hypokalemia has more than tripled in the U.S. population since 1999 due to increased consumption of processed foods high in sodium. 

Though sodium and potassium work together to regulate nerve signaling, blood pressure, and muscle contraction, excess sodium can deplete potassium as it stimulates its excretion through the kidneys. 

Those on a ketogenic diet may also be at risk of low potassium levels. 

Potassium and water help deposit glycogen in muscles and liver cells. Glycogen is naturally depleted during the early phases of keto-adaptation, which causes water shedding and can lead to potassium loss. 

Excess fluid intake, frequent vomiting, diuretic medications, and diarrhea are also common causes of low potassium, as too much water and fluid loss can imbalance or deplete electrolytes. 

Additionally, chronic stress or traumatic events, such as surgery, can cause a significant drop in potassium levels. 

Research published in Anesthesia found that potassium levels decreased in patients who experienced anxiety before an operation. It’s believed this is due to the release of stress hormones, which can interfere with potassium metabolism and trigger electrolyte imbalances. 

Testing potassium levels

Normal blood potassium levels range from 3.5 to 5.2 millimoles per liter (mmol/L), with deficiency being diagnosed when levels are lower than 3.5 mmol/L. 

Here are the serum potassium ranges to evaluate the severity of hypokalaemia:

• Mild hypokalemia: 3 to 3.4 mmol/L

• Moderate hypokalemia: 2.5 to 3 mmol/L

• Severe hypokalemia: less than 2.5 mmol/L  

However, 98 percent of potassium is stored in cells, and only two percent circulates in extracellular fluids and the blood. This means that conventional blood tests may not accurately reflect the body’s potassium stores.

Though blood tests can diagnose a severe clinical deficiency, a more reliable way to determine potassium levels is to perform an intracellular potassium red blood cell (RBC) test. 

A potassium RBC test measures the potassium concentration in red blood cells, offering a more comprehensive analysis that can quickly detect low potassium.

Best sources of potassium 

Despite bananas being commonly listed as a primary source of potassium, along with other fruits such as oranges and apricots, vegetables are the best sources of this crucial electrolyte. 

Leafy green vegetables are rich in potassium, with one cup containing approximately 500 to 800 milligrams. This highlights the importance of consuming 7 to 10 cups of vegetables daily to meet your potassium needs. 

Additionally, meat and fish are also good sources of potassium and can contribute to your daily requirements.

Here are some of the top sources of potassium: 

• Beet greens

• Leafy green vegetables such as spinach, bok choy, and Swiss chard

• Cruciferous vegetables, including broccoli, Brussels sprouts, and cauliflower

• Avocados

• Mushrooms

• Squash

• Salmon

• Beef

• Chicken

It’s also important to consider the quality of the foods you consume, as organic produce is more nutrient-dense than conventionally farmed crops. 

A study published in Alternative Medicine Review found that organic produce provides higher levels of vitamins and minerals than conventionally grown vegetables.

Organic farming also prohibits the use of chemical herbicides and pesticides, including glyphosate, which is linked to cancer and reproductive harm.

Additionally, opt for wild-caught, organic, grass-fed, and free-range meats. Farm-raised fish and conventional meats are often treated with antibiotics and growth hormones, which could lead to antibiotic resistance and hormone imbalances in humans. 

Wheatgrass juice powder and electrolyte powder may also contain potassium and can be an excellent strategy to promote optimal potassium levels.  

However, it’s recommended to choose organic wheatgrass juice powder and opt for sugar-free electrolyte powders that contain at least 1,000 mg of potassium per serving. 

Key takeaways

Potassium is essential for various critical physiological functions, including heartbeat regulation, nerve signal transmission, and muscle relaxation.

Some of the most common low potassium symptoms include insomnia, muscle cramps, and constipation. More severe deficiencies may cause hypertension, an irregular heartbeat, and anxiety.

Consuming plenty of potassium-rich foods and taking a potassium-rich electrolyte powder is an excellent strategy for promoting healthy potassium levels and reducing the risk of deficiency. 

FAQ

1. How do you feel when your potassium is low?

Symptoms of low potassium include fatigue, muscle cramps and weakness, insomnia, anxiety, and constipation. More severe deficiencies can lead to elevated blood pressure, anxiety, and abnormal heartbeats.

2. How can I raise my potassium quickly?

Eating a variety of potassium-rich foods can help raise potassium levels quickly. 

These foods include beet greens and other leafy green vegetables such as cruciferous vegetables, wild-caught salmon, grass-fed beef, and free-range chicken. Avocados, mushrooms, and squash are also excellent sources of potassium.

3. How do you fix low potassium levels?

The best way to remedy low potassium levels is to consume more vegetables, around seven to ten cups daily, and avoid sodium-rich processed foods. 

Additionally, electrolyte powders or wheatgrass juice powder help promote optimal potassium levels and reduce the risk of deficiency. 

4. Why do potassium levels drop?

Potassium levels can drop due to chronic stress, overhydration, vomiting, diarrhea, and the use of diuretic medications. 

However, low potassium is common and primarily caused by poor dietary habits, including excessive intake of processed foods high in sodium and a lack of potassium-rich vegetables.

5. What drink is high in potassium?

Orange and carrot juice are high in potassium, containing 496 and 689 mg per cup, respectively. However, these drinks are also high in sugar and can cause blood sugar fluctuations which exacerbate potassium loss and contribute to deficiency. 

Unsweetened electrolyte drinks that offer at least 1,000 milligrams of potassium per serving are the best beverages to promote steady potassium levels. 

Sources

1. https://pubmed.ncbi.nlm.nih.gov/1947601/ 

2. https://onlinelibrary.wiley.com/doi/10.1155/2012/742125 

3. https://pubmed.ncbi.nlm.nih.gov/18466657/ 

4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8989702/ 

5. https://ods.od.nih.gov/factsheets/Potassium-HealthProfessional/ 

6. https://pubmed.ncbi.nlm.nih.gov/32401639/ 

7. https://pubmed.ncbi.nlm.nih.gov/2386285/ 

8. https://pubmed.ncbi.nlm.nih.gov/20359265/