What Are the Causes of Low Potassium in the Blood?

Updated February 21, 2017

Potassium is a mineral found mostly in the cells in the body. Even the slightest change in blood potassium levels can have serious consequences on the muscles, nerves and heart. Our bodies need potassium to contract our muscles, regulate blood pressure and allow the heart to beat correctly. The kidney controls our body's potassium balance and it is responsible for eliminating excess potassium from the body through urine. When low blood potassium occurs, also called hypokalemia, cellular processes become impaired, resulting in weakness and other symptoms. Many different diseases, conditions and behaviours can cause low blood potassium levels.

Kidney Disorders

Since the kidneys are mainly responsible for our body's potassium balance, kidney disorders can cause low blood potassium levels when the kidneys are not functioning properly. Acute and chronic kidney failure can cause low blood potassium levels because these conditions render the kidneys relatively useless. Other kidney disorders that can cause low blood potassium levels include renal tubular acidosis. Potassium loss through the kidneys can also result from leukaemia or a magnesium deficiency.

Stomach and Intestines

Since potassium passes through our digestive tract when ingested, certain stomach and intestinal problems can cause low blood potassium levels. Prolonged or severe vomiting and diarrhoea can lead to a low blood potassium level. Excessive use of laxatives or enemas can as well because these can lead to a decrease in the amount of potassium that the body gets. Some people may also experience a potassium deficiency after a ileostomy operation. An ileostomy involves bypassing the large intestine by attaching the small intestine to the abdominal wall.


Certain medications can lead to a low blood potassium level. This can happen due to a interference with absorption of potassium or by expelling too much potassium from the body. Emphysema and asthma medications that can cause a potassium deficiency include bronchodilators, theophyline or steroids. Antibiotics that can cause a potassium deficiency include aminoglycosides. Other medications include diuretics such as water pills.

Shifting of Potassium Across Cells

Using insulin can cause this shift of potassium, leading to a low blood potassium level. Certain metabolic states including alkalosis can cause a low blood potassium level as well. This shift of potassium can cause a lower concentration of potassium in a person's blood.


Not eating enough can cause a low blood potassium level. When you are not eating enough, you may not be getting the amount of potassium that your body needs. A restrictive diet that does not include many potassium-rich foods can also lead to a potassium deficiency. Potassium-rich foods include fresh vegetables and fruits, dairy products and whole grains.

Cite this Article A tool to create a citation to reference this article Cite this Article


About the Author

Rose Kitchen is a freelance medical writer pursuing a bachelor's degree in sociology and education. She has a nursing background and is going back to nursing school in September 2011 for her R.N. Kitchen holds a certificate in anatomy and physiology and English and is pursuing certificates in natural and alternative medicine, fitness and nutrition and sports nutrition.