What Is Potassium Deficiency


Potassium deficiency, also known as hypokalaemia, occurs when the level of potassium in the bloodstream drops below the normal range. Potassium is an essential mineral that plays a crucial role in various physiological processes within the body. Maintaining the right balance of potassium is essential for the proper functioning of cells, tissues, and organs.

Role of potassium in the body

Potassium plays a pivotal role in our body's day-to-day operations, impacting various essential functions:

  • Heart function: Potassium is crucial for maintaining the electrical activity of the heart, ensuring proper heart rhythm and preventing arrhythmias.
  • Muscle contraction: It helps regulate our muscle’s ability to contract and relax, including smooth muscles such as in our digestive tract, where this relaxation and contraction facilitates the efficient movement of food and the digestion process
  • Nerve transmission: Nerve transmission is needed for cells to communicate with each other  to cause muscle movement
  • Fluid balance: It helps regulate the balance of fluids and electrolytes within and around cells, which is essential for maintaining blood pressure and hydration.
  • pH balance: Potassium helps to maintain the body's acid-base balance (pH), which is vital for metabolism1

Signs and symptoms of potassium deficiency 

Muscle Weakness and Cramps: Potassium is essential for proper muscle function, including muscle contraction and relaxation. A deficiency in potassium can lead to muscle weakness and frequent cramps. These cramps can be worse during physical exertion and exercise. 

Fatigue and Weakness: Potassium is involved in energy metabolism within cells. When potassium levels are low, cells may struggle to produce adequate energy, leading to feelings of fatigue and overall weakness. You may notice this fatigue begins to affect your daily life, making it more difficult to do normal day-to-day activities.

Irregular Heartbeat and Palpitations: Potassium plays a critical role in maintaining the electrical activity of the heart. Low potassium levels can disrupt the heart's rhythm, leading to irregular heartbeats (arrhythmias) and palpitations.2 

Nausea and Vomiting: Potassium imbalances can affect the digestive system. In cases of severe potassium deficiency, individuals may experience nausea and vomiting. As mentioned before, one of the roles of potassium is to help with smooth muscle contraction, particularly with the gastrointestinal muscles. Problems with the movements of these muscles can trigger feelings of nausea.

Tingling or numbness: Low potassium levels can disrupt nerve function. This disruption may lead to tingling or numbness, often starting in the extremities, such as the fingers and toes. This sensation is known as paraesthesia.

It's important to note that these symptoms can vary in severity depending on the severity of potassium deficiency. In some cases, you may not notice any symptoms until the deficiency becomes severe. 

Risk factors for developing potassium deficiency

Inadequate dietary intake of potassium-rich foods: One of the biggest risk factors for potassium deficiency is not consuming enough potassium in your diet. Potassium-rich foods include fruits, vegetables, legumes, and certain dairy products.

For women over 18 years old, the recommended intake of potassium is 2600mg, and for men over 18 years, the recommendation is 3400mg.

Certain medical conditions: The kidneys play a crucial role in regulating potassium levels in the body. Conditions that affect kidney function, such as chronic kidney disease or kidney failure, can disrupt the body's ability to maintain the proper balance of potassium. This can lead to a deficiency in much-needed potassium.3

Some gastrointestinal disorders, like chronic diarrhoea or conditions that cause excessive vomiting, can lead to potassium loss. This is because potassium is excreted through the gastrointestinal tract, and when this process is disrupted, it can result in lower potassium levels.

Medications that affect potassium levels: Certain medications can interfere with potassium levels in the body. This includes diuretics (water tablets), which are often prescribed to treat conditions like high blood pressure and heart failure. Diuretics can lead to increased potassium excretion, potentially causing hypokalemia. Other medications, such as laxatives and some antibiotics, can also affect potassium levels, as they also affect the excretion and absorption of fluids. 

Diagnosis of potassium deficiency 

Blood tests to measure potassium levels 

The most objective way to diagnose potassium deficiency is through blood tests, a simple blood test looking at the electrolytes. A normal potassium level in the bloodstream typically ranges from 3.5 to 5.0 mmol. Levels below this range can indicate hypokalaemia or potassium deficiency.4 

Evaluation of medical history and symptoms 

In addition to blood tests, doctors will take a thorough medical history and assess symptoms. Symptoms like muscle weakness, fatigue, irregular heartbeat, and tingling sensations may suggest potassium deficiency. Understanding the context of a patient's health and any underlying conditions is important for making an accurate diagnosis. 

Treatment and prevention

Dietary recommendations

If potassium deficiency is mild to moderate and not caused by a medical condition that impairs potassium absorption or retention, dietary changes can be an effective treatment and prevention strategy. Increasing the consumption of potassium-rich foods such as fruits (e.g., bananas, oranges, and avocados), vegetables (e.g., potatoes, spinach, and broccoli), and legumes (e.g., beans and lentils) can help restore potassium levels. 

Potassium supplements  

In cases of severe potassium deficiency or when dietary changes alone are not enough, potassium supplements may be prescribed by a healthcare provider. These supplements should only be taken after discussion with a healthcare professional, as excessive potassium intake can cause issues. 

Managing underlying medical conditions 

If an underlying medical condition (such as kidney disease or gastrointestinal disorders) contributes to potassium deficiency, addressing and managing that condition is essential. Treating the underlying cause can help prevent recurrent potassium deficiency. 

Importance of balanced nutrition  

Beyond potassium deficiency, maintaining a balanced and nutritious diet is crucial for overall health. A well-rounded diet provides essential nutrients, including vitamins, minerals, and macronutrients, that support various bodily functions. It's essential to recognise that potassium is just one component of a healthy diet, and a varied and balanced diet is essential for optimal health. 

Complications of untreated potassium deficiency 

Impact on cardiovascular health 

Untreated potassium deficiency can have significant effects on the health of the heart. Potassium is very important for maintaining the electrical activity of the heart and regulating heart rhythm. As we mentioned before, without adequate potassium, individuals may experience irregular heartbeats and palpitations. In severe cases, untreated hypokalaemia can lead to life-threatening cardiac arrhythmias, where the rhythm is so abnormal that the heart is no longer able to pump correctly. If this happens, oxygen is unable to reach vital organs such as the brain and back to the heart muscles, which can be fatal. 

Muscle and nerve dysfunction 

Potassium plays a critical role in nerve signal transmission and muscle function, leading to muscle weakness and cramps if deficient. They can also lead to sensations of tingling, numbness, or paresthesia. These symptoms, though not immediately debilitating like paralysis, can significantly diminish someone’s quality of life, making everyday tasks challenging and uncomfortable.

Furthermore, in severe cases, this may develop into paralysis and an ability to move altogether.  The inability to move can be an alarming and frightening experience, highlighting the critical role potassium plays in our everyday movements and activities.

Kidney-related issues 

Untreated potassium deficiency can strain the kidneys as they attempt to conserve potassium, potentially leading to kidney-related problems. Additionally, if you already have underlying chronic kidney disease, potassium deficiency can worsen. The kidneys are already weakened and have to use compensatory methods to conserve potassium more than a healthy kidney. Therefore, worsening potassium deficiency can put even more strain on the kidneys.


It is crucial to appreciate that untreated potassium deficiency can have serious health consequences, and these complications can become life-threatening if left untreated. Therefore, if there are concerns about symptoms related to low potassium, or you are on medications that can affect potassium levels, it is essential to seek medical attention promptly. Diagnosis and proper management of potassium deficiency can prevent these complications. In most cases, hypokalaemia can be managed acutely to avoid any severe consequences, but it is important to get to the root of what caused the low potassium in the first place to avoid further episodes. 


  1. Kowey PR. The role of potassium. In: Lobo RA, Crosignani PG, Paoletti R, Bruschi F, editors. Women’s Health and Menopause: New Strategies — Improved Quality of Life [Internet]. Boston, MA: Springer US; 2002 [cited 2023 Sep 4]. p. 151–7. (Medical Science Symposia Series). Available from: https://doi.org/10.1007/978-1-4615-1061-1_18 
  2. Thu Kyaw M, Maung ZM. Hypokalemia-induced arrhythmia: a case series and literature review. Cureus [Internet]. [cited 2023 Sep 4];14(3):e22940. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8989702/ 
  3. Yamada S, Inaba M. Potassium metabolism and management in patients with CKD. Nutrients [Internet]. 2021 May 21 [cited 2023 Sep 4];13(6):1751. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8224083/ 
  4. Falk RS, Robsahm TE, Paulsen JE, Stocks T, Drake I, Heir T. Fasting serum potassium and long-term mortality in healthy men. BMC Public Health [Internet]. 2021 Apr 13 [cited 2023 Sep 4];21(1):711. Available from: https://doi.org/10.1186/s12889-021-10738-4
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Chavini Ranasinghe

Bachelor of Medicine, Bachelors of Surgery - MBBS, University College London

Bachelor of Science in Global Health - BSc (Hons), University College London

Chavini is a junior doctor currently working within the NHS. She also has several years of experience within medical education and has published multiple scientific papers on a wide range of topics. Her exposure to clinical practice and academia has helped her to develop an interest in sharing accessible and accurate medical information to the public.

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