Life with Fibro and MECFS - Why do blood draws make me sick?
FIBROMYALGIA,  MECFS - Myalgic Encephalomyelitis / Chronic Fatigue Syndrome

Why Do Blood Draws Make Me Sick?

Are you one of those chronically ill patients that dreads blood draws? Have you ever asked yourself this question?

‘Why do blood draws make me sick?

Why do I experience more chronic pain and flare-ups of symptoms after a blood draw?

In general, most people who have their blood drawn don’t experience serious side effects, but it’s fairly common for some patients to experience a brief sting at the injection site. Perhaps they also feel a bit lightheaded or tired after a blood draw as well. These are normal reactions and most people improve quickly with rest and a good snack afterwards.

But for patients like me, blood draws can be a horrible part of frequent visits to the hospital to manage chronic illness.

It’s not because I’m afraid of needles or get queasy at the sight of blood. (I’m not and I don’t.)

For years, I’ve suffered through blood draws and experienced fibro and MECFS crashes within minutes of my blood being drawn. The more blood they take, the worse I get. The aftermath is always severe.

Side effects from my blood draws include:

  • PEM crash (post exhertional malaise)
  • Extreme exhaustion and muscle weakness
  • Migraine
  • Nausea
  • Cramps
  • Dizziness and lightheadedness
  • Widespread pain
  • A cold, clammy sweat right after the procedure
  • Hot and sweaty later
  • Brain fog
  • Pale skin
  • Fainting depending on how much blood they take (My favorite blood technician Elaine knows me for this. That’s how we met!)
  • Worse than usual insomnia the night after my blood test

These crashes typically last 48 to 72 hours, but they have gone longer depending on how much blood is taken, and especially if I’m menstruating.

No matter how much I prep ahead or rely on my husband to do other activities at the hospital like paying and collecting my prescriptions so I can rest, I still get sick. Yesterday I walked to my blood test and walked out. Today I was flat on my back until 2pm and couldn’t sit up without experiencing more pain, nausea, and migraine pressure. I’ve taken an hour to write this post and then it’s back to bed for me.

Does anyone else experience this with fibromylagia and ME? I asked on Twitter and FM/MECFS patients replied.

I clued into blood draws and the toll they take on me in 2015 and brought it up with my rheumy back then. He didn’t believe me.

Less than six months later, I’d moved to Tzu Chi Buddhist Hospital and had a new neurologist who also didn’t believe me. I left him, and found my current rheumatologist and he seemed pretty keen to test my blood at every appointment.

Once again, I wondered if my doctor would believe me. I brought it up and he looked skeptical as he ordered yet another blood test.

At that point, there was no option but to do my test the day of my appointment and let him see what was happening. That day, the tech took a whopping amount of blood – and I promptly slid off my seat in the lab.

My tech wanted me to go to ER. I had my husband wheel me into my appointment approximately one hour afterwards and all I can say is that Dr. Chen was shocked by my appearance and lack of energy.

He wanted me to go to ER. I wanted to go home. (I did go home because I’ve experienced this before and I knew I needed rest, not more tests.)

After that appointment, we decided to reduce the number of blood draws I do to try and take the stress off my health.

Personally I feel that this has more to do with my MECFS diagnosis but after further reading, I’ve learned it could be fibromyalgia too.

Why do blood draws make me sick?

I decided to do a bit of research into this to try and understand why this keeps happening.

First off, it’s good to know that Fibromyalgia and MECFS patients experience glitches in how our bodies perceive pain.

Myalgic encephalomyelitis was classified as a neurological disease by the World Health Organization in 1969. Fibromyalgia is also classified as a lifelong disorder/disease of the central nervous system. Researchers have noted blood flow irregularities in both of these conditions, but I couldn’t find any information about blood flow being related to blood draws and FM/MECFS flare-ups.

Since Fibromyalgia and MECFS are neurological diseases that are driven by the central nervous system, it’s easy to see that a rogue CNS is responsible for amplified pain that shoots through the body and can hit anywhere.

“Because pain pathways throughout the body are amplified in fibromyalgia patients, pain can occur anywhere, so chronic headaches, visceral pain and sensory hyper-responsiveness are common in people with this painful condition.”

Daniel Clauw, MD, Professor of Anesthesiology. Medicine (Rheumatology) and Psychiatry at the University of Michigan. He serves as Director of the Chronic Pain and Fatigue Research Center.

It’s not unreasonable to conclude that something as small as needle can cause a hyper-responsive reaction with pain and exhaustion, which are hallmark symptoms of both diseases.

My central nervous system boots things into high gear and amplifies that pain everywhere. And since most patients experience some fatigue and are told to rest after a blood draw, it’s easy to see why my energy levels would be affected since my body operates with an energy deficit.

Are doctors aware of this?

None of my doctors warned me or seemed to be aware of this type of reaction until I brought it up.

On blood draw days, you can always see that I am sick. And now my doc has seen it too.

So, how do YOU react to blood draws?

To close, I’ve included A Chronic Voice’s March writing prompts:

I’m no stranger to blood draws or being poked and prodded. I’m not afraid of needles, since I have to inject twice a week for my arthritis. But I do recognize that I need to incorporate some new routines to lessen the impact of blood draws.

I’ve begun incorporating more prep for my hospital routine on blood draw days. Rest before my test and after is essential.

My husband asked me to go out to dinner with him tonight and I said let’s wait and see. Today he said he could see that I was right to say we needed to bump our dinner date.

If you’re experiencing the same type of reaction as me when you get your blood drawn, try a deep breathing technique to help you stay calm. I use deep breathing for almost everything, and it’s so helpful. (A massive perk to being professionally trained as a vocalist is that my deep breathing skills are impressive.) Since my central nervous system is constantly out of whack, this is an easy technique that I can use anywhere and at any time to try and calm it.

Deep breathing is almost instinct for blood draws now and I’m honestly not bothered at all by the procedure. It’s the aftermath that gets me every time.

If having your blood drawn makes you anxious, try closing your eyes and pretending you’re somewhere else. I freely admit I have never watched my techs draw blood and that’s totally fine. Some patients feel better without having to see that needle enter your arm and watching blood flow into those vials.

A no-brainer. Smiling at your blood technician and chatting with them makes blood draws easier. Plus I like to joke to ‘take it easy on me’. They always laugh at that. Having a good relationship with nurses and blood technicians is as simple as offering a smile and having a good chat with them while you’re waiting.

It also reminds them that you’re human. Can you imagine doing hundreds of jabs a day? I bet it gets pretty boring. My techs always give me a big hello when they see me rolling in.

Now that I’ve discussed this with my doctor and he has confirmed with his own eyes what happens to me any time he orders blood tests, he’s stopped ordering so many. It took three doctors before someone finally realized I was serious about how blood draws were affecting me.

Never STOP advocating for what is best for you.

While I realize that blood draws are essential since I’m chronically ill, I can still minimize the impact by learning when to do them and when to say no. Sometimes my doctor wants me to push through because we need an accurate reading on inflammation, but he’s also ok with me saying no when I need to.

I’ve learned to stop going through with unnecessary tests unless they are 100% necessary. I didn’t realize I could do that when I was a new patient. As a veteran patient, I know what is expected each month and what I can say no to unless it’s absolutely required.

I relish the moment when I’m feeling better after a blood draw. And if hubs brings me cookies, believe me, I’m going to indulge since good cookies are so hard to find in Taiwan.

I’m also going to relish my time between now and my next blood draw!

I'm a chronically ill Canadian who has been living in Taiwan since 2006. I'm a bit of a jack of all trades! I love art, gardening, flower arranging, reading (that's an understatement if you've seen my GoodReads profile), and snuggling with my cats. Animal videos make me cry. I hate cooking. Nothing makes me happier than seeing my garden bloom! Learning about new cultures and exploring the world has been my thing since I started traveling at age 19. A self-professed autodidact, I can speak comfortably on many different subjects and hold a special place in my heart for science, technology, law, health and medicine, and history. You can find me nerding out at home most of the time due to being chronically ill and housebound. If I'm not engaged in one of the activities listed above, I'm probably building websites. Check my About page under Carrie Kellenberger to learn why I'm taking you on this journey with me through My Several Worlds. I can't wait to get to know you better!


  • The Joyous Living

    Your blog title drew my eye while looking at the Chronic Pain linkup 🙂 I just got my blood drawn this morning in fact and thankfully I didn’t have any issues. but I definitely can not look at my arm when the needle goes in and the blood is being taken. makes me all queasy and light headed. Sorry it is a difficulty for you. x

    Joy at

  • Katie Clark

    Wow, I haven’t had this. However, I do have bad experiences with OV and blood draws if they try to use my job existent veins olin my left arm. After a pretty traumatic time in the hospital with viral meningitis (they had to call the ER nurse in to get the I V in), I’ve been pretty nervous . I now let them know we’ll in advance NOT the left side. You’re do right, that we can’t ever stop advocating for ourselves.

    • Carrie Kellenberger

      After speaking to a number of friends who have fibro and MECFS diagnoses, we think it might be related to MECFS more than fibro, but I’m definitely not the only one. I’ve got more responses coming in on Twitter and it’s so interesting to hear others confirm their experiences. It’s also strange that I haven’t seen this discussed much! Thanks for stopping by, Katie!

  • Pain Reaction

    Wow, I did not know blood draws could be that detrimental to some people! I just had one done a couple of days ago and I always get fatigued a bit earlier in the day than usual but that’s about it. Although when I was doing chemo I had blood drawn every week and it certainly drained me pretty quickly. That seems like a reasonable thing to happen though. For a chronically ill person, it’s more than a temporary inconvenience. I hope you get all the cookies you want after your next draw!

  • Anne Sweet

    One thing I have noticed haven’t spent so much time in hospitals is that everyone is different when it comes to needles. My nurses are used to me and know that even though it can be difficult to draw blood from me sometimes it really doesn’t bother me at all. The really weird thing is, if I accidently cut myself. even a little nick with a knife at home, it makes me feel like passing out. It must be psychological in my case for sure. I’m sorry it makes you so sick though, what a pain.

  • Claire

    I have quite a fear of blood draws as I passed out on my very first one when I was a child and still have that memory. They used to make me feel very unwell too, although lately not so much. But perhaps it was because they were only taking one vial and sometimes it’s been in the double digits!

  • Catherine Green

    I think it stands to reason that you should have some side effects when blood is taken, especially fatigue, and yet we are expected to go about our business as usual. I can’t comment personally because the doctors don’t have much need for my blood, I can probably count on one hand the number of times I’ve had it taken in my life!

    • Carrie Kellenberger

      I have awful luck with blood draws. They need to check constantly because of the meds I’m on for spinal arthritis. At one point, they were checking every 3 weeks when I was on a chemo med, and I barely left my bed when that was happening. Thanks so much for stopping by, Catherine!

  • Alison Hayes

    Carrie – thanks for that analysis! It makes sense to me that if your CNS is hyper-responsive, blood draws would become damaging/exhausting for you as a patient.

    I know that with my FND , stress is a major trigger, and so things like blood draws are likely to get me twitchy.
    My focus is on not moving DURING the draw – and just before and after instead. Some techs work well with me, but I’ve had a few people get uncomfortable or anxious when I get symptomatic – which then increases my likelihood of having symptoms!

    I’m so sorry that your blood draws have such an impact on you – and glad that you finally found a doctor that believed you!

    • Carrie Kellenberger

      I’m hearing the blood pressure and blood flow is also an issue for patients with MECFS and blood draws, so who knows? I just started learning more about it and didn’t feel educated enough to write about it, so I linked instead.

      Yes, I have favorite techs for sure and they are the best. I’ve posted a video on my MSW IG about the noise and lights happening at this station during draws, and some patients suspect I’m reacting to the extra stimuli as well. Who knows? Glad my doc believes me and that the CI community came through for me once again and said, YES, I GET THIS. I do love awareness for this reason. I feel way less alone when I find out I’m not the only one. Take care, Alison!

  • MAndy Farmer

    I’ve not heard of this problem. My issue with blood draws is making sure that I am well hydrated for a better experience. Also, with fibro, I find the tourniquet extremely painful. But when I recently visited a hematologist, the nurse used an AV tourniquet, It’s flat and does not roll-up. It has a quick-release button so you can loosen it quickly. It was amazingly, more comfortable. Now I carry one with me. Like these

    • Carrie Kellenberger

      It is so interesting to hear all the comments rolling in, Mandy. I am surprised no one has written about it, but when I asked, the ME community was particularly responsive in saying it’s a problem for them. I will check out that tourniquet link. Thanks so much for sharing and for stopping by. It’s always good to hear from you!

  • Sheryl

    Thanks for using this opportunity to share about blood draws making you literally sick. I’ve never heard of it unless severely anaemic, so this was very interesting (albeit painful for you)!

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