Potassium deficiency

Potassium is a mineral that is essential for your body's functions. It helps your nerves, muscles and the heart to work properly. It also helps to move nutrients and waste to and from your cells.

Potassium deficiency is when you have very low levels of potassium in your blood. It's also called hypokalaemia.

Some people with potassium deficiency don't have any symptoms.

If you do have symptoms, they may include:

• weakness and fatigue
• feeling tired
• muscle cramps
• an arrhythmia — skipped heartbeats or an irregular heartbeat

There are many causes of potassium deficiency.

The amount of potassium your body needs is affected by:

• the climate
• your level of physical activity
• using diuretic medicines ('water tablets')
• how much sodium you eat (as found in table salt)
• your kidney function

You may have a higher chance of developing low potassium levels if you:

• become dehydrated — due to vomiting or diarrhoea
• take certain medicines, such as diuretics — these increase the amount of potassium you lose via your urine (wee)
• have some endocrine (hormone) or metabolic conditions
• have low magnesium levels
• don't get enough potassium from your diet — this is very rare
• take lots of laxatives for constipation

See your doctor if you are concerned about your potassium levels.

You should speak to your doctor before starting potassium supplements. This is because having too much potassium can also be dangerous.

Potassium deficiency is diagnosed with a blood test. Sometimes, your doctor may also arrange a urine test.

Your blood test may be done as part of a routine medical examination. They might also check your potassium levels if you have high blood pressure or kidney disease.

If you are found to be potassium deficient, your doctor may refer you for more tests. These tests may help find out the cause of your low potassium.

There are different ways that potassium deficiency can be managed.

Potassium supplements

If you have low potassium, your doctor may recommend you take a supplement.

You should only take a potassium supplement under the guidance of your doctor. Having too much potassium in the body can cause serious health problems.

Intravenous potassium

If your levels are very low, you may need to be given potassium through an intravenous (IV) drip in hospital.

Other treatments

Depending on the cause of your potassium deficiency, your doctor will also talk about any other treatments you need.

They may also talk about ways to prevent the problem coming back.

If your medicines are causing the potassium deficiency, your doctor may tell you to eat more foods that are high in potassium. Alternatively, they may suggest a change in your medicines.

Severe hypokalaemia can be life-threatening. The most serious complication is an arrhythmia (irregular heartbeat), which can lead to cardiac arrest.

Most people can prevent potassium deficiency by eating a healthy, balanced diet with:

• fruits
• vegetables
• breads and cereals
• nuts and legumes

If you have an increased chance of hypokalaemia, talk to your doctor about your potassium levels.

You can read more about how potassium levels are tested on the Pathology Tests Explained website.

Eat for Health (Opens in new tab) has advice on the amount and types of food you need, including potassium (Opens in new tab).

You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with 24 hours a day, 7 days a week.