Symptoms of Low Potassium (Hypokalemia)

Here are 7 signs and symptoms of potassium deficiency.

Weakness and fatigue

Weakness and fatigue are common signs of potassium deficiency for a few reasons:

• when blood potassium levels are low, your muscles produce weaker contractions
• a deficiency may affect how your body uses nutrients in a way that can result in fatigue

For example, some evidence shows that a deficiency could impair insulin production. This can result in high blood sugar levels and less available glucose, which functions as energy for your cells.

Muscle weakness and cramps

Muscle cramps are sudden, uncontrolled contractions of the muscles. They can occur when blood potassium levels are low and can be painful.

Within skeletal muscle, potassium helps relay signals from your brain to stimulate contractions. It also helps end these contractions by leaving the muscle cells. When blood potassium levels are low, your brain cannot relay these signals as effectively.

This results in more prolonged contractions and is thought to contribute to muscle cramps. Cramps are unlikely to occur with mild or moderate hypokalemia, but they may happen with severe hypokalemia of less than 2.5 mmol/L of potassium.

Digestive problems

While digestive problems have many causes, they may occur with severe hypokalemia.

Potassium helps relay signals from your brain to muscles located in the digestive system known as smooth muscle. These signals stimulate contractions that help your digestive system churn and propel food, so it can be digested.

With low potassium levels, contractions in the digestive system may become weaker and slow the movement of food. This could cause digestive problems like bloating and constipation.

Abnormal heartbeat

Potassium also plays a vital role in maintaining healthy heart muscle contractions.

This is because the flow of potassium in and out of heart cells helps regulate your heartbeat. Low blood potassium levels can alter this flow, resulting in abnormal heart rhythms known as heart arrhythmia.

Heart arrhythmias can also be a sign of a serious heart condition. If you notice any abnormal changes to your heart rate, seek immediate medical attention.

Tingling and numbness

Though more common in people with high potassium, or hyperkalemia, those with potassium deficiency may also experience persistent tingles and numbness.

This is known as paresthesia and usually occurs in the hands, arms, legs, and feet.

Potassium is important for healthy nerve function. Low blood levels can weaken nerve signals and result in tingling and numbness.

While occasionally experiencing these symptoms is harmless — like if your foot falls asleep from lack of movement or sitting in an awkward position — persistent tingles and numbness may be a sign of an underlying condition.

If you experience this, it’s can be helpful to speak with doctor.

Polyuria (frequent urination)

Polyuria is a condition where you pee more than usual.

The kidneys are responsible for balancing your body’s fluid and electrolyte levels and removing any waste through the urine.

Low potassium levels may impair your kidneys’ ability to concentrate urine and balance the blood’s electrolyte levels, leading to increased urination. You may also notice increased thirst, known as polydipsia.

Excessive urination may lead to lower levels of potassium. Therefore, it’s important to speak with a doctor if you notice a sudden change in how often you urinate.

High blood pressure

Having the perfect balance of electrolytes is important for maintaining healthy blood pressure.

You may be aware that consuming too much sodium can increase blood pressure in some people. Yet, few people know that too little potassium in the diet can have the same effect.

Potassium helps your kidneys get rid of excess sodium via urine. If there isn’t enough potassium in the blood, the kidneys reabsorb sodium back into the bloodstream, potentially leading to high blood pressure over time.

This most often occurs with a low dietary intake of potassium — and specifically with hypokalemia.

Therefore, getting enough potassium in your diet may help maintain healthy blood pressure in some individuals.

While it’s generally rare to develop potassium deficiency, certain illnesses or other factors can cause it, including:

• chronic diarrhea, which can be caused by the overuse of diuretics or laxatives, irritable bowel disease, or infections
• certain medications, such as diuretic drugs
• eating disorders, such as anorexia nervosa, purging, or laxative abuse
• under-eating or malnutrition
• Cushing’s syndrome
• hyperaldosteronism, where there is excess aldosterone, a steroid hormone, in the blood
• kidney failure
• kidney disorders, such as Bartter syndrome, Gitelman syndrome, and Fanconi syndrome.
• hypomagnesemia (low magnesium levels)
• excessive sweating

If you’re taking certain medications for kidney disease, such as diuretics, and you suspect your potassium is low, consider speaking with a healthcare professional. They can review your blood tests and adjust your medications or diet as needed.

If you’ve experienced chronic fluid loss or have misused any medications, seek immediate medical attention.

In most cases, hypokalemia will need to be treated by a healthcare professional.

Mild to moderate hypokalemia is typically treated with oral potassium supplements. In some cases, a healthcare professional may also need to adjust any other medications or treat underlying causes, like diarrhea, vomiting, or eating disorders.

A potassium-rich diet is usually not enough to treat hypokalemia, since most potassium in food is paired with phosphate, not potassium chloride. Hypokalemia often also involves a chloride deficiency, so it’s best to treat both deficiencies with potassium chloride supplements.

Usually, 60–80 mmol of supplements per day for a few days to weeks is sufficient for treating mild to moderate hypokalemia. That said, it’s important to always follow the recommendations of a healthcare professional.

In severe hypokalemia cases, intravenous (IV) treatment may be recommended. This should be strictly monitored by a healthcare professional due to the high risk of rebound hyperkalemia, or high potassium, which can be fatal.

Though diet alone usually will not resolve hypokalemia, it’s still beneficial to increase your intake of potassium-rich foods, like fruits, vegetables, beans, and nuts.

The National Academies of Sciences, Engineering, and Medicine (NASEM) recommended daily intake (RDI) for potassium is 2600 mg for females and 3400 mg for males.

However, as around 90% of potassium is absorbed from food, the percent of the Daily Value (DV) listed on food labels remains at 4,700 mg. Keep this in mind to help you ensure you’re consuming enough.

Here’s a table of foods that are excellent sources of potassium:

While increasing your potassium intake won’t likely raise your low potassium levels, eating a potassium-rich diet is still beneficial to your health.

Few people meet the daily recommended potassium intake, which is 3,400 mg for males and 2,600 mg for females.

Nevertheless, hypokalemia is rarely caused by dietary deficiency alone. It can be caused by a number of factors, including fluid loss, malnutrition, shock, using certain medications, and medical conditions like kidney failure.

Common signs and symptoms of potassium deficiency include:

• weakness and fatigue
• muscle cramps
• stiffness
• tingles and numbness

If you think you may be deficient, it’s important to speak with a healthcare professional. Potassium deficiency can have serious health consequences.

If you notice any sudden changes in your breathing or heartbeat, seek immediate medical attention.

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