New way of measuring blood volume


Active Member
There is a relatively new method of measuring blood volume – carbon monoxide rebreathing. It is much cheaper and easier than the old way (nuclear isotopes).

It is being used at NASA to study hypovolemia in astronauts, as well as in sports science and altitude studies.

This machine is undergoing approval for medical use this year. It is made in Denmark. The company has a scheme to lend out a machine for two months free of charge to scientists who will put it to good use.

I think this will allow scientists to finally do some good research on low blood volume in ME/CFS and orthostatic intolerance because it will be much more affordable.
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Active Member
Here is a video of the test. Note: shows blood being taken.

Anyone who is qualified to take blood can easily be trained to run the test. No nuclear medicine qualifications required!


Active Member
The medical version has now been certified for use in Europe. We should see it showing up here and there very soon!

The company has a free loan program, allowing any interested scientists or doctors to apply to borrow a unit:


Active Member
Where did you find out about this loan program?
It’s on the company’s website at the link I posted above (looks like a blue square rather than a URL). It’s for interested doctors or scientists who can install the device temporarily in a suitable lab or clinic.


Active Member
Some research on blood volume, done with the older isotope method:

Blood Volume Status in ME/CFS Correlates With the Presence or Absence of Orthostatic Symptoms: Preliminary Results

In the next few years, we will see CO rebreathing blood volume testing available in hospitals and autonomic labs.

Low blood volume can be addressed with volume expansion (e.g. increased salt and fluid intake, fludrocortisone) and volume redistribution (e.g. compression leggings).


Active Member
Upcoming research on blood volume and increased salt intake in POTS:

I suspect this research, with 50 subjects in Canada, will use the Detalo Health technology to check blood volume.


Active Member
@Cort , forgive me if I’ve already suggested this, but how about a blog article on this new method of measuring blood volume?

I would love to see CFS and dysautonomia researchers have access to this, and then see it being used clinically to guide treatment.

(I found out that I don’t have low blood volume, but my specialist and I thought I did for almost two years be ause there was no way of measuring it, so ruling it in or out in a timely fashion is a cause close to my heart.)

The two scientists who own the company are very nice and have interesting research areas. I’m sure they would be happy to be interviewed.

Blood volume measurement can help in so many medical areas, ranging from blood disorders to heart failure to kidney problems, as well as the ones we know about here, such as CFS, Long COVID and dysautonomia. It would be a good addition to any hospital with a dialysis unit, and could serve many others apart from dialysis patients.

Plus the carbon monoxide rebreathing method is inexpensive and radiation free.

I know I sound like a salesman, but I am just a patient who wants to see the technology out there doing good!

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