What is Hypokalemia?

Hypokalemia is a medical condition where the potassium level in the bloodstream is too low. Low levels of potassium can be detected via an ECG or electrocardiogram. Normal potassium levels are between 3.5 mmol/L and 5.0 mmol/L. You are said to have hypokalemia if your potassium level is below 3.5 mmol/L. Mild hypokalemia can be managed with changes in diet. Severe hypokalemia occurs when your potassium level is below 2.5 mmol/L, which can be fatal and requires immediate medical attention. Potassium is an important mineral and electrolyte for the normal functioning of muscle and nerve cells in the body. Your body requires potassium for the normal contraction of muscle cells, especially in the heart. Even the slightest alteration of the potassium level can adversely affect your nerves, muscles and heart. Potassium helps to regulate your heartbeat and helps your heart muscles to regulate blood pressure. If you have low potassium levels, you have a higher risk of developing an abnormal heart rhythm, including cardiac arrest and bradycardia.

The kidneys are responsible for controlling potassium levels in your body by excreting excess potassium through sweat and urine. Other chemicals in the body, and hormones like aldosterone, also help to regulate potassium levels in the bloodstream. Insulin, which is produced by the beta cells in the pancreas, also affects potassium levels by increasing potassium absorption by the cells. When you have low potassium level, there is an imbalance of potassium in the body because this process is not functioning properly. Low potassium level can also occur when there is excessive loss of potassium through urine without the mineral being adequately replaced. Patients who have AIDS, eating disorders like bulimia and anorexia nervosa, alcoholism, and those who have had bariatic surgery have a higher risk of getting hypokalemia.

Signs and symptoms of low potassium level

If you have mild hypokalemia, you may not develop any signs or symptoms. Usually, low potassium level is discovered through a blood test that is conducted when you are suffering from an illness or you are using diuretic medication. It is rare for mild hypokalemia to result in isolated signs and symptoms like fatigue or muscle cramps if you are not ill. You can speak to your doctor regarding your blood test results and what it actually means. Your doctor may recommend you change the medication that is adversely affecting your potassium level, or you may need to address an underlying medical problem that is resulting in low potassium. In some instances, mild hypokalemia can cause your blood pressure to rise or lead to abnormal heart rhythm. Abnormal heart rhythm is a worrying sign of low potassium level which may be a symptom of another medical problem like heart disease. Abnormal heart rhythm normally occurs in people who use digoxin medication or experience irregular heart rhythm like tachycardia where the heartbeat is too fast, bradycardia where the heartbeat is too slow or premature heartbeats.

The signs and symptoms of low potassium levels are not specific and are usually related to cardiac or muscular function.

The following are the common signs and symptoms of low potassium level.

  • Muscle cramps
  • Muscle aches
  • Polyuria
  • Weakness
  • Fatigue
  • Constipation
  • Heart palpitations
  • Psychological signs like depression or hallucinations

Severe low potassium can be life threatening leading to symptoms of ileus, respiratory failure, paralysis, and muscle tissue breakdown. In some cases, severe hypokalemia may result in hyporeflexia and flaccid paralysis. Other signs and symptoms of low potassium levels include vomiting, nausea and loss of appetite. If you notice any of the symptoms of hypokalemia, you should call your doctor or visit a hospital immediately.

Hypokalemia causes

There are many factors which can cause hypokalemia. Your body can lose excess potassium through bowel movements, sweat or urine. If you do not consume enough potassium, or you have a low magnesium level, it may result in low potassium or hypokalemia. Diarrhea and laxative abuse, as well as use of medications such as diuretics, are some of the main causes of hypokalemia. Your risk of getting low potassium increases when you use certain types of drugs like diuretics, which leads to loss of potassium. Also, using higher doses of drugs like penicillin, or taking beta 2 agonists to treat asthma, increases your risk of developing hypokalemia. There are also certain types of medical conditions which increase your risk of low potassium. If you have Bartter syndrome, which is a rare kidney problem that results in potassium and salt imbalance, it can lead to hypokalemia. Liddle syndrome is another rare medical disorder that causes hypokalemia.

Other medical conditions that can cause low potassium level include:

  • Hypethyroidism
  • Magnesium deficiency
  • Malnutrition
  • Familial hypokalemia
  • Cushing syndrome, a rare medical condition which occurs as a result of cortisol exposure.
  • Gitelman syndrome, a rare disorder of kidney that results in an ion imbalance in the body.
  • Diabetic ketoacidosis, a serious medical condition which occurs when there is insufficient insulin in the body. As a result, glucose cannot enter the body’s cells to be used for energy, so the body starts breaking down fat for energy instead. This might sound Hypokalemia occurs during treatment of diabetic ketoacidosis, where the fluids and insulin used, causes your potassium level to fall too low.


Before you begin treatment for hypokalemia, your doctor will have to carry out a few tests. These tests will help your doctor rule out other possible medical conditions like Cushing syndrome and renal tubular acidosis. Usually, hypokalemia is diagnosed through urine and blood tests that are used to check for mineral levels such as potassium and vitamins. Your doctor may also perform an ECG test to detect irregular heart rhythms that may occur because of low potassium. If you are diagnosed with hypokalemia, you may be required to be admitted to a hospital. While in the hospital, your doctor may treat underlying causes such as vomiting or diarrhea. You may be prescribed to take potassium supplements to help normalize your potassium levels. In case of severely low potassium levels, intravenous replacement may be required. During your treatment, your doctor may need to monitor your potassium levels to avoid it falling again. While you are at home, you can manage low potassium lavel by avoiding diuretics or laxatives that result in hypokalemia. Your doctor may prescribe you potassium supplements and follow a potassium-rich diet as part of your treatment.

Disclaimer: Please note that the contents of this community article are strictly for informational purposes and should not be considered as medical advice. This article, and other community articles, are not written or reviewed for medical validity by Canadian Insulin or its staff. All views and opinions expressed by the contributing authors are not endorsed by Canadian Insulin. Always consult a medical professional for medical advice, diagnosis, and treatment.