CLL Support Association
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Hello Friends

I was rushed to the A&E department of my local hospital a few days ago because of an illness unrelated to my Cll.The FBC carried out as part of the diagnostic investigation was made difficult because of problems in drawing blood.Three lengthy attempts before they were successful.Which I always find traumatic.The FBC results were OK apart from an elevated potassium count of 5.7.I am not sure if my potassium level has been checked before.The hospital staff were not unduly concerned about it.Should I be?

Best Wishes


6 Replies

When you mentioned difficulties with drawing your blood sample and the hospital staff not being worried about a high potassium level, I wondered if that was because they were aware that the repeated attempts to draw blood would have ruptured blood cells, releasing potassium from within the blood cells into the plasma, hence raising the level. Sure enough, a quick Internet search confirmed this explanation:

My specialist always requests two sets of tests at a minimum; the blood cell counts (CBE) and the metabolic panel, with the latter measuring potassium. I gather many of us only get the CBE test done, so you may not have previous potassium levels to compare your latest result. If you want to track and plot your blood counts, or find out the normal range for a blood test, they're documented here, along with a spreadsheet for your use:

Note that reference states the normal range for potassium to be between 3.5-5.3.



That's very interesting, Neil (about high potassium sometimes being due to ruptured cells leaking into the blood sample). Thanks. I've learnt something new today!


P.S. Django, I do hope you're feeling better now.


Hi Bob,

We should combine ourselves -- see my post five days ago... Complications, complications, complications.

My diagnosis was Hypokalemia - Low Potassium - mine was 2.9 - rising with K tablets and some bananas.

A normal range for potassium is between 3.6 and 5.2 millimoles per liter (mmol/L) of blood.

A newspaer article:-

But a normal, healthy person could not get a fatal dose of potassium through food – and certainly not through a few bananas.

Catherine Collins, a dietician at Kings College London told BBC recently that to ingest enough potassium to kill you, you’d have to eat around 400 bananas at once.

That’s all at the same time.

Which would be pretty hard.

Hope your "K" problem is resolved soon.


“Being cheerful keeps you healthy. It is slow death to be gloomy all the time.” (Proverbs 17:22,


Before treatment (Imbruvica) I did CBC (in US) and Chem 12 every Three months. After start of my treatment I do CBC monthly and Chem 12 every other month.


Another cause of spurious high potassium reading, is the request by the sampler for the patient "to make a fist". Whilst this helps the vein to stand out, muscle contraction removes sodium and raises potassium levels in the blood around the muscle (which is near the site of the sample). This happened to me during an NHS check-up. A second phlebotomist took a sample - no fist, no hesitation and no bruise afterwards. Oh and the potassium levels were normal!

The experience has made me very aware of the varying competencies of phlebotomists!

Here's a link to a news item about this which appeared in 2008:

Take care,



Thanks John

I was asked to make a fist during the time the nurse was struggling to draw blood.This could well be the source of the high reading'

Best Wishes


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