High blood potassium

Clinically: Hyperkalaemia · also high potassium, raised potassium, high blood potassium

electrolyte

This describes what this condition typically looks like. It is not a diagnosis and cannot tell you whether you have it -- patterns overlap, results vary between labs, and the same numbers mean different things in different people. Diagnosis usually rests on Potassium, interpreted alongside symptoms and history rather than read off a report.

unverified These explanations are written to be easy to read and have not yet been checked against a source. The ranges and measurement notes on this page show theirs.

definition unverified

Potassium in the blood is above normal. Kidney disease and some medicines are common reasons.

Plasma potassium above the normal range. There is no internationally agreed definition; the European Resuscitation Council defines hyperkalaemia as a plasma potassium above 5.5 mmol/L and severe hyperkalaemia as above 6.5 mmol/L. Causes fall into reduced renal potassium clearance, release of potassium from cells, and impaired shift of potassium into cells.

caveats unverified

A high result is sometimes false. Blood cells can break while the sample is taken and let potassium out. Clenching and relaxing your fist during the blood draw can also raise the result for a short time.

No clinical version written yet.

The typical lab pattern

What the diagnosis rests on

The results a diagnosis is actually made on.

Potassium

high

—

Defined (European Resuscitation Council) as plasma potassium above 5.5 mmol/L; above 6.5 mmol/L is severe. There is no internationally agreed definition. A high result with normal kidney function should prompt a check for a false rise from cells breaking in the sample.

Consistent with it

Fits the picture, but not enough on its own.

Estimated glomerular filtration rate

low

ref ≥ 60

Kidney function is the strongest risk factor. The risk of high potassium rises as eGFR falls, and in chronic kidney disease it is typical once eGFR is below 15.

Followed over time

Tracked once it is established.

Glucose

either

ref ≤ 99

Insulin with glucose is a common emergency treatment, so blood glucose is checked every hour for at least 2 hours afterwards. Both low and high glucose can follow.

How it usually feels

Feeling sick to your stomach · occasional
Feeling tired all the time · occasional
Muscles feeling weak · occasional
Noticing your heartbeat · occasional
Pins and needles, or numbness · rare

Frequencies say how often a symptom accompanies this condition — not the other way round. Most people with any of these symptoms do not have this.