Why high levels of potassium are bad for your body

Why high levels of potassium are bad for your body

posted onJune 21, 2021

Potassium is a mineral that helps our nerves, cells, and muscles function properly, and aids in regulating blood pressure, heart rhythm, and the water content in our cells. Adults should aim to have about 3,500 – 4,700mg every day, which can be easily done through your diet. Foods like spinach, potatoes, salmon, edamame and soybeans, bananas, and avocado will give you the potassium your body requires to function at its best.

However, it’s also possible to have too much potassium, especially if you take multivitamin and mineral tablets every day, on top of eating a balanced diet with plenty of potassium-rich foods. If you’re slightly over the recommended amount, your kidneys begin to do their job of filtering and flushes out toxins and unnecessary vitamins and minerals from your bloodstream, simply removing the excess potassium. However, for reasons including kidney disease, your potassium levels may get too high. This is known as hyperkalemia or high potassium, and can actually be just as bad, if not worse, than having too little potassium.

A normal range of potassium is anywhere between 3.6 and 5.2 millimoles per liter (mmol/L) of blood, while your potassium levels are considered critically high if they reach 5.5 mmol/L and above.

What causes high potassium levels?

Health problems

Hyperkalemia may be caused by underlying health problems, including:

  • Kidney failure — this is the most common cause of hyperkalemia, as the excess potassium is not being filtered out

  • Dehydration

  • Type 1 diabetes

  • Internal bleeding

Certain medications

Medications that may affect your potassium levels include:

  • Certain chemotherapy drugs

  • Angiotensin-converting enzyme (ACE) inhibitors

  • Angiotensin receptor blockers


Taking potassium supplements alongside multivitamin or mineral supplements may cause your potassium levels to reach dangerously high levels. If you take multiple supplements, it’s important to look at how much of each mineral and vitamin is in them, and take care not to overload your body.

Muscular breakdown

Heavy alcohol or drug use binges can break down your muscles, causing larger amounts of potassium to enter the bloodstream, which could lead to hyperkalemia. This breakdown of muscles can also be caused by trauma, including burns or crashes, which can injure a large number of muscle cells.

Symptoms of high potassium

The symptoms of hyperkalemia you experience depends on how high your body’s potassium levels are. If you’re only slightly above the recommended amount, you may not show any symptoms, and your kidneys will naturally flush out the excess over time. However, if your potassium levels are high enough to cause symptoms, then you may experience any of the following:

  • Tiredness or weakness

  • Feeling numb or tingly

  • Nausea or vomiting

  • Difficulty breathing

  • Chest pains

  • Palpitations or irregular heartbeats

In the most extreme cases, hyperkalemia may cause paralysis or heart failure, and may even be fatal if symptoms are left untreated. If you feel like you’re experiencing any of the symptoms listed above, you should contact your GP. They will then conduct a test for hyperkalemia, using either a urine or a blood sample. If your potassium levels are deemed dangerously high, you may need to stay in the hospital until the concentration levels out again.

How to treat high potassium

If you’re suffering from high potassium levels, you’ll need to be treated as quickly as possible to avoid overwhelming your kidneys and potentially causing long-term damage to how well they function. The cause of your high potassium levels will determine the course and duration of your treatment.


If hyperkalemia is caused by kidney failure, you’ll need to undergo hemodialysis treatment, which uses a machine to filter and remove waste from your blood. Hemodialysis typically lasts for about four hours, and should be done three times per week, but the length of time depends on a number of factors, including how well your kidneys work, how much fluid you gain between treatments, how much waste you have to remove, and your size.


You can be prescribed medication to keep your potassium levels at a level which your kidneys can manage more easily on their own. These may be:

  • Calcium gluconate — this reduces the effect of potassium on your heart

  • Resin — this binds with potassium, allowing it to be removed during a bowel movement

  • Diuretic — this encourages urination, increase the amount of potassium excreted by your kidneys

Drinking more water

Staying well-hydrated means that more water passes through your kidneys, which can help keep your potassium levels controlled as you urinate more. Drinking more water is encouraged to keep your kidneys and bladder working, but cannot fight against critically high hyperkalemia.

Monitoring salt substitutes

Specific salt substitutes can be high in potassium, so while you might think you’re making a healthier choice, this may not be the case. If you’re worried about your levels, look out for potassium chloride in any foods you eat, which may be found in processed foods and energy drinks.

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