Haematacrit levels up and down ?


I was recently diagnosed with JAK2 + Polycythemia.

I have had weekly venesections for the past 4 week aimed at reducing my haematacrit level from 50% to 44%

Last Wednesday my haematacrit had come down to 40% and I was over the moon as was the medical team . My haematologist said no need for further venesections and to see her again in early February and if my haematacrit had crept up again she would arrange further venesections . I had to go in for INR test today and they checked my blood levels again . Turns out my haematacrit has gone back up to 44% in the space of 5 days .

My question is

Is this normal? I thought it would take at least weeks for the haematocrit to increase by this amount?

I am new to all this so not sure how this all works ?

Thanks for taking the time to read this and may I wished everyone a Merry Christmas and a Happy and healthy New Year

Kind regards


20 Replies

  • My partner was diagnosed with this age 33 ,he had 2 venesection a week but he has now been put on referon interferon 3 injections a week hasn't had venesecton now for 2 months and levels have all stabled. He's also on wafarin for 6 months but he's in range now with that as well. But with my partner they said his is myeloproliferative neoplasms not just pv as he has a 3rd of them all and they can't pin point the one he has which is scary .

  • Thanks Brook

    Good to hear your partners levels have stabilised - hope it stays that way

    Kind regards


  • Me too it scares me more than it does him haha ,thank you x

  • 44 is still quite low - my haem works to 45, sometimes 50, depending on the cell mix. but i agree i'd be disappointed and surprised at the quick rise ; do you know which are the main culprits - red white or platelets?

  • Hi Jane

    Both red cells and platelets are up but platelets more so.

    I am more confused at the speed of the rise than anything .



  • i think platelets have a very short life expectancy - about every 5 days you make a new lot - so they could well be the main culprits causing the HCT rise. My haem is not keen on doing lots of venesections if platelets are the problem as he says it make me produce lots of smaller, odd shaped, "sticky" platelets which can increase the risk of clotting, and reducing the risk of clotting is why we have venesections! When I got to the stage that my platelets pushed my HCT over 50 my haem got me on hydroxy.

    I am not an expert so don't take my word for it!

  • Hi Jane

    Thabks so much for taking the time to answer .

    It is quite a complicated condition isn't it ? Takes a bit getting your head round and as you say, its not always straight forward .

    My haematologist is very kind and approachable so I will discuss it with her .

    Once again thanks for taking the time to answer.

    Merry Christmas to you !



  • :-)

  • HI dianne,

    My husband is pv jak 2 positive he used to have weekly then monthly venesections after 3 years of doing this he went on to hydroxy he managed 8 months without a venesection but he's back to having them every 3 months now.

    His consultant likes his hct level to be between 0.45 - 0.48 it's OK to go to 0.50 but that's the top of the scale.

    My husband was 42 when he was diagnosed we were so frightened, but in all we just get on with our life as normal. He does suffer fatigue apart from that he's fine.

    He's seeing his consultant today we hoping his bloods are OK.

    Mind yours gamma gt liver function levels keep rising but we not sure why.we read up that asprin can cause this. We still waiting for answers.

    Take care


  • Hi Tracey

    Thank you so much for your reply . Thus condition takes a bit of time to get your head round doesn't it ? Knowing what is significant with blood results and also how your body responds to the different types of treatment and medication etc. Also how hydration plays a major role as Pete has just hi lighted to me .

    I really hope your husband gets good results today .

    Thanks once again for taking the time to reply and also I hope you and yours all have a Merry Christmas and a happy and healthy 2017

    Kind regards



  • We just at the hospital. Johnathans hct was 0.51 so he's just had a venesection.

    He's well in himself.

    Take care

  • You too


  • Hi Dianne

    I have PV jak2+ and treated with venesections. HCT levels can be effected by hydration. We should all keep well hydrated by drinking plenty of water but I always make sure I'm well hydrated before blood tests to give a consistent level. Do you think that could have had an influence on your reading?

    Just remember we're all individuals and our bodies react in different ways so try not to worry. Your reading is still good at .44. Mine varies between .42 and .48.

    Best wishes


  • I'm not sure about the hydration having effects on blood results, but it's played a major part in my husbands fatigue. He stopped coffee in October and feels sp much better.

    He stopped drinking tea on Monday too and started drinking warm water.

    He definitely feels much better.


  • Thanks for your reply and advice Tracy

    It's all a bit of a learning experience at the moment

    Kind regards

    Dianne x

  • Hi Pete

    Thank you so much for your reply - it is very reassuring . We were rushing about that morning when I had my bloods done so I may have not had as much to drink as I should and as you say hydration can affect haematacrit levels . It was just the speed of the rise from 40% to 44% that bamboozled me a little but what you have said possibly explains it :-)

    Thank you so much

    Kind regards


    Ps Merry Xmas to you and yours!


  • No problem Dianne.

    Also, as you've only just started having venesections, it can take a while for levels to settle down.

    I was diagnosed just over 2 years ago and it takes a while to adjust to living with PV - I've now learnt not to overthink things or worry too much. My HCT has gone down of its own accord before so hopefully yours may now have done the same!

    A Merry Xmas to you too and a happy healthy new year.


  • Thank you so much Pete

    I don't think of myself as much of a worrier at all normally but with this I feel as though I've become a little obsessed with my blood levels at the moment .

    I suffered a DVT & PE in January of this year which they now think was related to my then undiagnosed polycythemia. Because of my previous history of thrombus I was concerned when my haematocrit levels jumped up so quickly . As you say it is early days just yet and as time passes I guess you get to experience ups and downs of red cells and platelet levels . My platelets seem to be up and down from week to week between 650 and 900 .

    Again, as you say these levels can be erratic and are sensitive to stuff like adequate hydration etc.

    They took my bloods again today and if my HT is above 44% they are doing another venesection next week. I have a really good team looking after me and I am sure they have a handle on all this - it's just me wanting to understand it all .

    Once again

    Thanks so much Pete - i really appreciate your kind advice


  • Hi dont stress to much just try and aim for 2 litres of water a day i am only 1 year diagnosed with pv jak2 pos. and am finally settling down about it all i was so freaked by it. when first diagnosed had 1 venesections every week for 6 weeks then 1 a month now im every 3 months. my hemo is wonderful i dont see him for 6 months now he sets himself an alarm when im due for my bloods and rings me if theres a change. he said dont you worry ill worry for you. told me to go and get a casual job and seriously i feel so much better. when i first was diagnosed my legs and hands were so swollen i couldnt walk but im now running around like a lunatic get your blood tests from your doctors and study them and read everything about this disease you will definately start to relax when you hear what everyone else is going through and start to understand

    Lots of strength

    Tracey from Cairns

  • Thank you so much Tracey .

    As you say probs in 6 months time I will feel an "old hand" at this and in that time confidence increases - it's just feels a little alien at the moment for me to be examining my blood results etc when I've previously just toothed along oblivious about this stuff flowing through all our blood system ! Ha ha

    You keep well too and here's wishing you a Very Merry Christmas and a Happy and Healthy 2017

    Best wishes



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