Worried private finger prick tests are in accurate?

A friend of mine has told me if I massage my finger to help the blood out my results could be in accurate so now I'm very worried.

I've used blue horizon and medicheck to get my results. The results were tsh climbed from 6.5 in January, 7.5 march and 9.28 May.

I am now on 50mg thyroxine but worried because I have to massage the finger to egg the blood out I've had wrong results. I don't squeeze it but I have to massage slightly higher up I don't massage on the site of the finger prick. My last test i had to stab myself 3 times to get it all out. I drink water and wash hands in warm water but I'm a slow bleeder.

My friend had hers done private through medicheck and her tsh was 5.8 I think then just had it done a few months later on nhs and was under 3 so she's now doubting private are accurate for her tsh to halv, which has worried me.

Any reassurance? I'm worried now my results all been wrong and maybe not even had a thyroid issue.


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24 Replies

  • Your test won't be affected by a slow release of blood or massaging your finger or not. They just won't.

    This is classic anxiety, which as you know, is a symptom of hypothyroidism and any underlying anxiety issues will be exacerbated by a low thyroid.

    You and your friend are different. Her high, then low result could be due to taking her meds too near to the blood test time, the time of day and so on, her medication may even be working.

  • She concerned me yes that's why I asked here. I'm not overly anxious about it just concerned are the finger prick tests accurate to do.

    She is very worried. As her tsh has halved ok an NHS test and she did it same time of day fasted at 9am.

    Thank you for your reply.


  • Does your friend have high antibodies on any of these tests? If she has autoimmune thyroid disease, even if undiagnosed, then the results will vary anyway.

  • No her antibodies were normal last test.

  • My TSH with Blue Horizon was nearly the same as previous NHS test. 0.01 different.

  • Thank you that's good to know.

  • The ranges for the blood tests differ for each lab so it's important to take that into consideration as well rather than just concentrating on the number

  • I did mention this to my friend but she doesn't seem to think a change in range effects the actual result number.

    The nhs range for tsh is a little broader 0.35-5 and private is 0.27-4.2. Her nhs result was about 4 and private 5.8 which had made her doubt the finger prick private tests are reliable which has of course made me worry.

  • I'm sure that the private tests are more than reliable, in fact, the Blue horizon test was instrumental in getting my diagnosis of Pernicious Anaemia. Without it I would be in a worse mess than I am now.

    I'm not sure why but even NHS ranges differ across the country. Something to do with machines they use for testing and the average results for the area, I think.

    TSH isn't the most reliable way to test for thyroid function as it is produced by the pituitary gland and it changes throughout the day but it is an indicator of the need for more thorough testing. The best time for testing is early morning as this is when it's at its highest.

    However, from the look of your friends TSH it looks as though her thyroid is struggling and she could probably benefit from some replacement thyroxine.

  • Thank you.

    It's also how I got diagnosed hypothyroid. My tsh was 5.35 on the nhs test last summer and t4 about 10.2 (7-17 range) but my gp said I wasn't ill. I was so ill all winter so I got private tests done which showed with blue horizon it was climbing from 6.5 to 7.5 then 7 weeks later 9.28. Weirdly my ft4 was about 14/15 (12-22) so not too low but finally my gp said I was hypothyroid at 9.28 and I'm on thyroxine. Without the private testing I'd be in a much worse place. It made me so ill undiagnosed for so long. I'm so glad I found this place as without everyone here I'd never have known anything was wrong with me and taken my gp word that 5.35 was normal as gospel.

    My friend has fertility problems and has asked her gp for a trial of thyroxine and was told she didn't need it and they wouldn't until her tsh hit 10.

    Thank you for your help.


  • And I forgot to say she isn't on thyroxine.

  • Tbh, I would just carve my own path here and not get caught up whatever is going on with your friend. You (us all) have limited enough energy to get through whatever trails are thrown at you without the unknowns of your friend's problems.

    I say that kindly. It's up to her to investigate what's going on.

    Would you feel better messaging Paul(?) from Blue Horizons to give you the statistics on how accurate finger prick testing is compared to venepuncture? Because it's an interesting question/query. x

  • Oh how do I contact Paul? I'd be interested in knowing that.

  • Thanks you.

  • If you squeeze your finger hard then the blood cells may burst and so the sample wouldn't be usable. BH would contact you to request another sample. So you wouldn't have inaccurate results, more like NO results! Gently stroking the finger to help the blood to flow is perfectly ok, and the results should be fine. :)

  • Great. Thank you so much.

  • I've only known RBCs burst due to osmosis. Interesting.

  • Hi Jingyd,

    I have your message, Thank you. Interestingly I was reading the WHO guidelines on fingerprick testing (the health organisation not the band) and they mention on a child to rhythmically and gently squeeze and release the wrist. I tried it on myself and it appears to work, so another trick up our sleeves!

  • Oh I shall try that next time. Would massaging a finger cause any issues? I'm just concerned if finger prick tests are less acurate as I rely on them with my thyroid.

    Thank you.


  • If you stay away from squeezing at the puncture point you should be OK.

    Don't laugh, but I used to milk goats, and I find the goat milking technique useful for fingers too! Gentle and gradual application of squeezing fingers.. I need to do a video really don't I!

    As others have said, haemolysis blood is very obvious at the Laboratory and will be rejected or commented on.

  • Hi Paul, how accurate are the finger prick test results compared to venepuncture?

  • Hi Bombus, it is accurate enough for Becton, Dickinson and Company to offer it as a blood collection method alongside their Vacutainers.

    Technical details differ dependent on the Laboratory instrument and reagent system and ultimately BD say It is the laboratory’s responsibility to determine reference

    intervals for all analytes base upon the tubes used for skin puncture blood specimens by that laboratory. The clinical laboratory should establish/verify its reference ranges if changing specimen collection tube types and sizes, as this could potentially affect analytic results from patient samples.

    As the tubes take several drops of blood it gives comparable results to vacutainers - I cannot say the same for single drop methods such as blood spot techniques.

  • Many thanks!

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