Pernicious Anaemia Society
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Non-PA symptoms: insomnia / trouble sleeping, fast pulse

An odd symptom that I've had for some time is insomnia and trouble sleeping, and a fast pulse and heart rate. Sometimes I wake in the night with my heart pounding, and have difficulty getting back to sleep. For a couple of months this summer I had the worst insomnia ever (slept about an hour a night), and was always thirsty, frequent urination. Diabetes test was negative. Endocrinologist and my primary care doc could not figure out what it was. Things improved a bit to where they are now, PA was diagnosed a few weeks ago.

I thought a PA symptom was excessive fatigue. I have that only a couple of days each month.

Is this something else or just weird PA symptoms?

7 Replies

At the risk of being like the person with a hammer thinking everything is a nail, I have to ask if you and your medics have considered thyroid as a cause?

Both hyperthyroidism and hypothyroidism can cause sleep problems and palpitations. High heart rate is usually hyperthyroidism.

The very first symptom I displayed of hypothyroidism that was sufficient to make me consult a GP was plantar fasciitis - which would cause painful feet particularly on rising in the morning.

However, don't expect PA to resolve with two weeks of B12 treatment. It can take very much longer for the fullest achievable benefits of B12 to be reached. So it might be nothing else, but I did not want to walk on by without making the suggestion that thyroid be properly considered. (A single TSH test that is in range is not sufficient to rule out thyroid issues.)


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Thanks Rod! TSH has been tested over a couple years and I see it has climbed recently. I'll talk to my doctor about it, but my HMO (I'm in the US) is highly driven by test results and since they are all in range they are not inclined to do much about it. Range is 0.10 - 5.50 uIU/mL.

Results below, date is YYYY/MM/DD. I've got a graph which is more effective but can't see a way to attach it.

2012/10/24: 1.18

2014/02/23: 1.20

2014/09/10: 1.86

2014/11/06: 2.40


I wish you had Free T4 and Free T3 results as well. TSH is an inadequate test - but quite usual for medics to rely on it.


Tracy - You may find the website "Symptoms of B12 deficiency by Dr. Peter Osborne" very informative. It is on YouTube, created in Aug, 2012. I used to have fast pulse, pounding heart rate, fatigue, etc etc. Have been on monthly B12 shots for the past 7 months & all my issues have improved. Hopefully this message will give you some ideas.


The only thing I can think of is diabetes insipidus, which is not your usual sugar related diabetes that you would have been tested for, its a type of diabetes that makes you urinate a lot.

Maybe get tested for this?


I had a lot of trouble sleeping before B12 treatment and also palpitations. Both those have settled now. Hope yours resolve too but keep an eye on your thyroid function too.



I too had the rapid heartbeat as a symptom of low b12 and the insomnia. Interesting enough before it was discovered that I have b12 maladsorption . I was tested for thyroid before the b12 also. Perhaps thyroid troubles are also a symptom .


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