Home General Info & Awareness Pernicious Anaemia – What You Need To Know About The B12 Condition

Pernicious Anaemia – What You Need To Know About The B12 Condition

by InvisiblyMe
A cartoon nurse to the left holding a huge injection that's bigger than she is. To the right is a giant red blood cell. Above this is the post title : Pernicious anaemia, what you need to know.

I was diagnosed with Pernicious Anaemia (PA) a couple of years ago. It took long enough for anyone to even test my B12 levels after increasing symptoms, especially where exhaustion was concerned. The sad and frustrating thing is that despite diagnosis and treatment, I still struggle with PA. The way it is managed in the UK by the NHS is not always helpful for patients, and there are many out there campaigning to change this. Here’s what you need to know about PA.

What Is Pernicious Anaemia?

Pernicious anaemia (PA) is a form of B12 deficiency. Although it’s the most common form in the UK, PA is still considered a rare disease, with the Journal of Blood Medicine estimating that it affects 0.1% of the general population.

A drawing of a large red blood cell.

B12 is combined with intrinsic factor (IF) in your stomach, a protein that helps the absorption of the vitamin. Some people have a lack of IF and thus an impaired ability to absorb B12, often as a result of pernicious anaemia being an autoimmune condition that attacks the cells in the stomach. However, for some, Pernicious Anaemia doesn’t an identifiable cause. They are found to have acceptable IF levels and yet are still unable to absorb B12. In such cases, it’s thought that genetics / familial history of Pernicious Anaemia may play a role, along with other conditions.

It was called Pernicious because previously was a deadly condition, but thankfully science has been able to provide treatment to save lives of those with PA.

A lack of B12 (and/or folate) results in red blood cells being underdeveloped. Pernicious anaemia is a type of macrocytic anaemia, referring to the way in which fatter blood cells are less able to carry oxygen around the body (also termed Megaloblastic Anaemia).

How Is Pernicious Anaemia Different To B12 Deficiency?

B12 deficiency can be due to various reasons, including a diet that’s lacking in such important vitamins, Inflammatory Bowel Diseases, and certain medications. With adjustments to lifestyle and temporary or oral B12 supplementation, B12 levels can be increased and made stable. However, for those with PA, ingesting B12 doesn’t help as the stomach doesn’t absorb it. Levels will continue to drop after an initial B12 injection because the body is unable to maintain B12. Ongoing B12 injections, generally for life, are required for those with PA. If left untreated, pernicious anaemia can have serious complications.

Symptoms of Pernicious Anaemia

Pernicious Anaemia is a more insidious condition that can produce symptoms gradually over time and get worse without treatment. Symptoms can be quite generalised and overlap with other conditions, too, making it hard to diagnosed unless specifically tested for. Some people may have various symptoms, others just a few, and there will be varying degrees of each as the condition will obviously affect every individual differently. Common symptoms can include :

  • Tingling / numbness in hands/feet
  • Tiredness, exhaustion, significant fatigue
  • ‘Brain fog’, impaired thinking and memory
  • Flaking nails, dry skin
  • Shortness of breath
  • Dizziness, difficulty with co-ordination, vertigo
  • Fluctuating weight, gastrointestinal symptoms/poor digestion
  • Irritability, problematic sleep, depression, low libido, mood swings

Diagnosing Pernicious Anaemia

Due to often slow-growing, generalised symptoms, PA is often overlooked and many can be without treatment for years. It’s not included in most general blood work ups and so it’s important that if you find yourself with worrying symptoms that you request a B12 test specifically.

Blood tests can look for anaemia, folate deficiency and the size of red blood cells. Your GP should also keep in mind any symptoms you’re experiencing. The problem next comes with levels, which vary between countries and can often leave many without adequate treatment because they’re considered borderline. Tests are not always accurate and can lead to false positives, too.

It’s important to not only keep a record of symptoms, but to request a full work-up, to look at your Intrinsic Factor if there’s a deficiency, and ask for your levels so that you can have these for your own reference.

Diagnosis and treatment, if B12 deficiency is found, next moves on to a course of regular injections over a couple of weeks to assess your levels and your symptoms, and a follow-up blood test weeks later to see whether B12 has been retained by the body.

Treatment For Pernicious Anaemia

Treatment is generally via an injection in the upper arm of Hydroxocobalamin.

Sadly, many in the UK struggle with treatment for PA due to doctor’s surgeries limiting injections to once every 3 months. Other countries, other specialists, can often allow for more regular injections on a patient-by-patient basis. There has been a lot of discontent among patients and rallying trying to reassess treatment within the UK, as well as to educate and research more on the ways in which PA is diagnosed.

A cartoon nurse holding a huge injection needle.

There’s also debate as to whether blood tests are viable measures of PA; once treatment has been underway, blood tests can suggest higher levels of B12 than is necessarily accurate because they can report up to 80% of B12 that’s inactive and unusable.

I find that by month 3, I’m flagging quite drastically and things continue to go downhill until the injection. However, I never get adequate relief from symptoms. I don’t notice a huge improvement when I have my injection, just when it’s wearing out. This is quite common among those with PA, but many will also find huge benefit to injections and be okay to have them every three months. It really does vary. For those who don’t notice a big improvement, but do notice a huge problem at month 3, the rare few who have been able to seek help elsewhere from a compassionate doctor and have regular injections have gone on to find incredible benefit.

The injections are said to cost around £1 and doctors and nurses will say there’s no evidence that more regular injections are helpful, and flat out refuse to do them even every 6 rather than 8 weeks. It’s another reason I think the treatment for PA needs to be reviewed and for all doctors and nurses to be fully informed and put the patients first.

Frustratingly, some celebrities seem to have hit the headlines with ‘trendy’ B12 injections, which undermines the seriousness of pernicious anaemia and the difficulties many patients have with getting the treatment they need.

Find Support For Pernicious Anaemia :

Campaign For Change

The current petition on Change.org is a great one as it outlines the problems with treatment and requests consideration for injections to be made more readily available to patients. I’d really recommend those with PA, or who want to support the cause and those individuals struggling with the condition, to take a look and sign it. You can find it here.

Do you have any experience with Pernicious Anaemia? If you have symptoms and are concerned, please speak to your GP and request a check of your B12.


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Comedy Plus March 14, 2018 - 4:35 pm

I didn’t know about this. I hope you can get a shot each month rather than every three months. That doesn’t seem to be helping having to wait so long between shots.

Have a fabulous day. ♥

InvisiblyMe March 17, 2018 - 3:29 pm

It certainly doesn’t help a lot of people having to wait so long, it’s frustrating as I think most people struggling on three monthly treatment would happily pay the £1 per extra injection in the interim to see whether it helps them. Thank you for the lovely comment – have a great weekend 🙂

Ellie Strand, MSN RN APRN (Ret.) March 14, 2018 - 6:49 pm

Good article with helpful advice.

InvisiblyMe March 17, 2018 - 3:28 pm

Thank you, I’m pleased you find the post helpful 🙂

Georgina March 14, 2018 - 8:44 pm

I also struggle with PA. I know when I’m due my jab as I’m in bed by 8pm. Have you tried the spray you put under your tongue? I have found this, along with a daily folic acid tablet take the edge off the worst symptoms in the last few weeks waiting for the jab. I still feel crap, just not as crap as I did before xx

InvisiblyMe March 17, 2018 - 3:27 pm

I took supplements previously but they weren’t absorbed so I stuck to just injections, I wonder whether a spray would be any better.. Worth looking in to, and I’m glad you’ve found it helpful in at least taking the edge off. I can’t help but wonder whether treatment more regularly would be what we need to try as those that have been in a similar situation (little benefit noticed until feeling heaps worse by month 3) who were able to get injections every 3-4 weeks found a huge difference to how they felt. Thank you for sharing, Georgina, I really appreciate the comment! x

I tripped over a stone. March 15, 2018 - 1:14 am

That is so scary. I am anemic and have issues producing Ferretin which is the protein that carries iron. You are on your game, covered it all! The doc is slow to tell me the type of anemia I have but Iron deficiency due to low ferritin levels and B12 lacking, now I take a B12 shot EVERY FOUR WEEKS!!!! I’d be dead in 8. With iron daily. This is an excellent post, Caz.
. I wound up in the hospital for three days with blood transfusion and iron infusions. This has to be taken seriously!

InvisiblyMe March 17, 2018 - 3:24 pm

B12 every four weeks would be a huge no-no in the UK because GP surgeries just say “there’s no evidence treatment more regularly than every three months is any more helpful”. It’s a joke, because they don’t seem to care that you feel awful, and more awful still my month three. Ending up in hospital needing transfusions and infusions is definitely a lesson in just how important such issues and deficiencies really are – thank you for sharing, and I’m glad you liked the post! xx

KJ March 15, 2018 - 2:31 am

I have pernicious anemia too with 3 monthly injections. When I was first diagnosed I had weekly injections, then monthly. They consider 3 monthly for maintenance but like you, I find very little relief even though my b12 is now within normal range.

Have you had tests for other auto immune diseases? They seem to travel in groups. ?

InvisiblyMe March 17, 2018 - 3:21 pm

I’ve read a few posts, one in particular recently, where someone felt they didn’t have much benefit initially from each injection either, only really noticing how absolutely awful they felt by the third month. When these few people have somehow managed to get B12 every 3-4 weeks, they’ve actually shown a marked improvement of symptoms and felt heaps better, so it certainly makes me curious whether we’d be the same and find benefit from regular treatment. For me, it would just be a relief to not have such an awful third month. I have undifferentiated connective tissue disease and a recent fibromyalgia diagnosis, which don’t really help in narrowing things down to specific problems to target. Do you have other conditions that could account for your symptoms? Thank you for sharing your experience! x

KJ March 18, 2018 - 5:37 am

I know when I got the weekly injections (first 4 weeks) I felt so much better. Even though I was still low! Monthly wasn’t such a marked improvement but I felt better than I had. With 3 monthly I feel yuck all the time except for the week or two after the shot.

Im sure monthly would be more helpful too. I jokingly (not) asked the nurse if I could get needles and b12 to do my own! She laughed but didn’t reply. Ugh.

Why injectable b12 is on script I don’t understand! You can buy tablets even in supermarkets!

DeeDee March 15, 2018 - 2:44 am

This is new information to me, particularly with respect to how the UK deals with it. Thank you for educating us?

InvisiblyMe March 17, 2018 - 3:16 pm

I’m glad I could share something new for you & others! Thanks for the comment – have a lovely weekend 🙂

Ben March 15, 2018 - 9:44 am

Hi Caz,

wow.Sorry to hear that. I really hear about this disorder for the first time. I hope you are fine. Thank you for clarifying this topic !

InvisiblyMe March 17, 2018 - 3:16 pm

I think knowledge around B12 is becoming more well-known, but there’s less awareness perhaps about Pernicious Anaemia. Glad you enjoyed the article – thanks for the comment, Ben! 🙂

Suzanne Cox March 15, 2018 - 2:23 pm

I’m not a sufferer myself but I once had a friend who had to have the vitamin B12 injection every three months, agree with others that there should be the funds to provide it on a monthly basis.

InvisiblyMe March 17, 2018 - 3:15 pm

I think patients would be quite happy for the most part to pay £1 for each additional injection in the 3 month period, I really think the whole thing needs to be reviewed on the basis of individual symptoms. Thank you for the comment Suzanne! xx

Terri, Reclaiming HOPE March 16, 2018 - 3:40 pm

This is such an informative post Caz! Thanks for providing such important information — I’m definitely pinning and sharing on my FB page. I’m sorry it’s so difficult to get the treatment you need when you need it. I hope this changes soon.

InvisiblyMe March 17, 2018 - 3:12 pm

Thank you, Terri, I really appreciate that, as will others who need this medication! 🙂

Fibronacci March 17, 2018 - 6:01 pm

I was suspected of B12 deficiency and took shots for several months. Didn’t seem to really affect my energy levels any. Eventually I stopped taking them. Now I just take a regular multivitamin.

Christy B March 17, 2018 - 6:30 pm

This is new to me so thank you for educating us, as well as sharing your personal experiences!

Cobwebs March 18, 2018 - 12:59 pm

I knew nothing about this before reading your blog post… and although I’ve been taking (Doctor prescribed) Iron Tablets for over 6 years now, I still no nothing about why, how, what and because.
I’ve recently changed to a different doctor at my practise, so I’ve made a note of what you’ve said and am going to go and see him about this specifically – because I was shocked to realise that I have almost all of the symptoms you have listed. (Even reading them out to husband, who himself that it sounded like ‘me’)

Thank you so much for taking the time to type this out and post it.
Have a blessed rest of your day ~ Cobs. x

Cobwebs March 18, 2018 - 1:00 pm

no = know. [sigh] … my mother would have given me one of *those*looks for that mistake! lol

InvisiblyMe March 18, 2018 - 3:36 pm

I’m sorry you’re struggling with such symptoms too, it’s really no fun. With deficiencies (if they even find them without us requesting certain levels be checked) we’re often just given supplements & shown the door, but it’s important to if there’s a reason for it. Could be absorption, or diet, or another condition that’s affecting levels. Are your iron levels being maintained with the supplements okay? I’d definitely ask for your B12 to be checked, along with folate (and perhaps have your thyroid re-checked too as that can result in similar symptoms). Ask to jot down results once they come back so you can look them up for yourself (if you’re boarderline they’ll just mark things as being fine, which won’t help). I’m so glad you checked this post out & that it’s given you another direction to explore – fingers crossed the new doctor is willing to listen, get you tested & see what’s what! Thanks so much for taking the time to comment 🙂
Caz xx

Emma (Not Just Tired) March 20, 2018 - 10:48 am

Really informative post with helpful advice xx

InvisiblyMe March 20, 2018 - 4:27 pm

Thank you – I’m glad you found it informative! Have a great week, Emma =]

Nikki March 25, 2018 - 8:42 pm

This runs in my family so I am always aware I might get it one day. Hard with other symptoms I already have though. My doc does test my B12 though. I actually take B12 for nerve damage as is.

InvisiblyMe March 27, 2018 - 3:01 pm

I’m sorry you’ve got a family history of it, and I can see that you wouldn’t want this added to your health issues. With any luck this won’t happen, but I’m glad your doc is on top of testing and that you take B12 to keep your levels balanced. x


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