Why it hurts in fibromyalgia

You can find the video after the text

In this video, I will tell you about the scientific explanations as to why it hurts in fibromyalgia. 

My name is Andreas Persson and I am a physiotherapist and specialist in pain and pain rehabilitation. 

What I say in the video can be found in text together with references to the scientific studies that the things I say are based on. The link is in the description.

The disease fibromyalgia consists of many symptoms, but the most typical is pain.(1) There are many different opinions about the disease in healthcare and society. Many, even some who work in healthcare, do not believe that fibromyalgia exists, or that the symptoms are only due to psychological and social mechanisms.

It is common for healthcare professionals to say that we do not know the cause of fibromyalgia and thus suggest that there is no scientific knowledge at all about the disease. My ambition with the videos is to explain what the research shows so that anyone can understand the most likely causes of pain in fibromyalgia.

First, we have to clarify one thing, as some skeptical people who are not themselves affected may wonder. Do people with fibromyalgia have pain, and do it hurt as much as they say? There is a large amount of research that explains and supports the symptoms people with fibromyalgia have.

The same mechanisms that cause fibromyalgia and the associated symptoms have been triggered in several different ways in animals, such as mice. (2,3)

Experiments have triggered fibromyalgia-like generalized pain in normally pain-free persons.(4-6)

New imaging methods, such as fMRI, have shown that people with fibromyalgia activate the same areas of the brain that normally pain-free people activate when they are exposed to something that hurts. This means that you can see that it hurts in fibromyalgia through the way the brain is activated.(3,7,8)

In summary, there is overwhelming evidence that people with fibromyalgia really are in pain and not just are whining.

Now when that is cleared up, it is time to talk about the cause of pain in fibromyalgia. Why does it hurt? To answer the question, it is necessary to be a little more specific. The reason for this is that there are several different pain phenomena, which to some extent have different causes. 

The pain phenomena we are going to look at are:

Lowered pain threshold – that it hurts more easily when stimulating or straining the body

Amplified pain – that it hurts more when you are exposed to something painful

Unprovoked pain – pain when you do not strain the body or expose it to any sensory stimulation.

After-pain – pain that comes after a treatment or a physically strenuous activity

Widespread pain – that it hurts over a large area

Now is a good time for a confession. I do not know everything about the causes of the various pain phenomena in fibromyalgia. Neither do the scientists. There is much left to discover. But that does not mean we do not know anything. The scientists know a lot. 

The explanations I will present are my interpretation of the latest and best scientific studies and what the researchers know about fibromyalgia and chronic pain.

The explanations will be much more substantiated than the explanations, or rather myths that exist about fibromyalgia. Myths that also exist in healthcare.

Examples of some of the myths about the cause of pain in fibromyalgia are:

The pain in fibromyalgia is caused by repressed feelings after sexual abuse and other childhood traumas.(9-11)

Fibromyalgia is due to that the affected has lost his or her meaning in life and gains meaning by taking on the role of the sufferer of pain.(12-14)

The pain is due to the affected receiving secondary ”gains” by expressing that he or she is in pain. Examples of secondary gains are sick leave and increased attention among relatives.(15)

You may be wondering if people who work in healthcare believe in such things. If you do not believe me, please look at the text, where the statements are linked to articles, written by healthcare professionals that express these myths. 

But like I said, I do not know everything about the causes of chronic pain and fibromyalgia and I do not know everything about how to treat and manage the pain. Even though I worked with chronic pain patients for over 10 years. Making videos allows me to dive deeper into the research and learn more, and hopefully you will also learn things that you find interesting.

I hope that you want to be part of a journey where we can learn more about the causes, and how to treat and manage chronic pain.

If you want to be a part of this journey, click on the like button. Subscribe to the channel and share the videos you like on social media. It improves the possibility for me to continue making similar videos, and for you and others to see them. I don´t see the videos as one-way communication. I would like to have a conversation on the subjects with you. 

Write in the comments what you think and feel about what I am talking about, if there is something in the video you think can be improved, if there is something you think is good, and if there are other things you want me to make a video about

Now. Back to the topic.

As I said, in fibromyalgia, there are five different pain phenomena, lowered pain threshold, amplified pain, unprovoked pain, after pain, and widespread pain, of which we will look at the most probable causes.

Lowered pain threshold

We start with a lowered pain threshold.

First, there is no doubt that those with fibromyalgia have lowered pain thresholds. That is, that they hurt more easily. It has been found in many studies. Here are some examples.(16-20)

Many with fibromyalgia experience this when they get a hug or a pat on the back, or when they wear tight-fitting clothes, and also when they load the body in different ways.

To explain the causes of lowered pain threshold and the other pain phenomena, you need to meet Åke.

I can not brag about that I am a professional illustrator, but I have done my best to illustrate what I want to describe so that anyone can understand it.

Here we see what happens inside Åke’s body when he experiences something painful (in this case an apple that falls on his arm).

The pressure of the apple on the arm causes pain receptors on nerves to be activated and sends a signal to the spinal cord, where the signal activates knew pain nerves which send it on to the brain stem and the brain, which leads to the experience of pain.

To make the pain system easier to understand, we will look at a model, where you can see what happens with the pain signals. 

Here you can see the signal that comes from the pain nerves in the body. You can see how the signal activates new nerves in the spinal cord and how it is sent up to the brain stem and the brain.

The pain nerves in the body where the pain signal starts will be called peripheral pain nerves and pain nerves in the spinal cord that receives the signal and sends it further up towards the brain will be called spinal pain nerves.

Other sensory nerves, communicate other sensations from the body, such as touch, cold, and heat. They will be called sensory nerves.

To activate peripheral pain nerves, a stronger stimulation is required than to activate sensory nerves. This is quite logical because more powerful stimulation, such as hard pressure, severe cold, or heat is something that risks harming us. 

The function of pain is partly to prevent us from injuring ourselves. This means that it is rational that the peripheral pain nerves send pain signals during powerful stimulation so that we will stop doing what is hurting us. 

The pain threshold can be tested in several ways. One way is to press with something called an algometer, harder and harder until the person who is examined feels pain. The pain thresholds for heat and cold can be tested through a temperature-controlled metal plate on the skin. 

When testing the temperature thresholds, the test starts with the plate at the body temperature which is about 32 degrees Celsius on the skin, and either raise the temperature until it hurts, which tests the pain threshold for heat, or lower it until it hurts which tests the pain threshold for cold.

In healthy, normally pain-free people, the pain threshold is determined by the level at which the stimulation, that is the pressure, the cold, or the heat, activates the pain nerves in the body sufficiently so that a pain signal is sent up to the brain stem and brain. When you press light, only the sensory nerves are activated, but when you press hard, the peripheral pain nerves are also activated.

But it is not enough that the peripheral pain nerves are activated for it to hurt. The pain signal must be strong enough for the spinal pain nerves to be activated. If there are only weak signals with a long time in between, in the peripheral pain nerves, the signals are not passed on.

But when the pressure is sufficiently hard so that a strong signal is created in the peripheral pain nerves, the signal continues up through the spinal pain nerves to the brain stem and the brain, which means that the experience of pain is created.

What, then, is the reason why the pain threshold is significantly lower in people with fibromyalgia?

This could be because the peripheral pain nerves have become more sensitive to pressure, heat, and cold. The things that make peripheral pain nerves more sensitive to stimulation are injury and inflammation in the body. 

An important characteristic of fibromyalgia is that no damage or inflammation can be found in the painful area.(1,3) This suggests that increased sensitivity in the peripheral pain nerves is not the cause of lowered pain threshold in fibromyalgia.

Another possible cause is that the spinal pain nerves are more sensitive to incoming signals from the peripheral pain nerves. This would mean that a signal from peripheral pain nerves is passed on to the spinal pain nerves even though it is weak. 

This is probably part of the explanation, but we know that many people with fibromyalgia can experience pain even with very light stimulation, for example when pulling a cotton swab over the skin.(1,19)  This is probably too low stimulation for the peripheral pain nerves to be activated.

For the pain that people with fibromyalgia experience, with such light stimulation as when touched with a cotton swab, another explanation is required. Researchers have seen that signals in sensory nerves can switch over to the spinal pain nerves in the spinal cord.(21,22) 

This means that a light touch can be perceived as pain in those with fibromyalgia because the touch signals are switched over to the pain pathways and are sent as pain signals up to the brain stem and the brain.

So to summarize, the most likely causes of lowered pain threshold in fibromyalgia are more sensitive spinal pain nerves that pass on weak signals from the peripheral pain nerves and that sensory signals from the sensory nerves are transmitted to the pain pathways in the spinal cord.

But what is the reason why the spinal pain nerves are more sensitive and that sensory signals are transmitted to the pain pathways in fibromyalgia?

We will talk more about that in the next video, where I will also talk about the other pain phenomena people with fibromyalgia experience.

If you liked this video, press the like button and share it on your social media. If you want to see more similar videos, subscribe to the channel. Write in the comments what you think and feel about what I am talking about, if there is something in the video that you think can be improved, if there is something you think is good, or if there is something else that you want me to make a video about. 


1. Hawkins R. Fibromyalgia: A Clinical Update. J Am Osteopath Assoc. 2013;113(9):680-9. 

2. Sandkühler J. Models and Mechanisms of Hyperalgesia and Allodynia. Physiol Rev. 2009;89(2):707-58. 

3. Harte SE, Harris RE, Clauw DJ. The neurobiology of central sensitization. J Appl Biobehav Res. 2018;23(2):e12137. 

4. Staffe AT, Bech MW, Clemmensen SLK, Nielsen HT, Larsen DB, Petersen KK. Total sleep deprivation increases pain sensitivity, impairs conditioned pain modulation and facilitates temporal summation of pain in healthy participants. PLoS One. 2019;14(12): e0225849. 

5. Schuh-Hofer S, Wodarski R, Pfau DB, Caspani O, Magerl W, Kennedy JD, et al. One night of total sleep deprivation promotes a state of generalized hyperalgesia: a surrogate pain model to study the relationship of insomnia and pain. Pain. 2013;154(9):1613-21. 

6. Shimada A, Cairns BE, Vad N, Ulriksen K, Pedersen AML, Svensson P, et al. Headache and mechanical sensitization of human pericranial muscles after repeated intake of monosodium glutamate (MSG). J Headache Pain. 2013;14(1):2.

7. Pujol J, López-Solà M, Ortiz H, Vilanova JC, Harrison BJ, Yücel M, et al. Mapping Brain Response to Pain in Fibromyalgia Patients Using Temporal Analysis of fMRI. PLoS One. 2009;4(4):e5224.

8. Williams DA, Gracely RH. Biology and therapy of fibromyalgia. Functional magnetic resonance imaging findings in fibromyalgia. Arthritis Res Ther. 2006;8(6):224. 

9. Abbass A. Somatization: Diagnosing it sooner through emotion-focused interviewing. J Fam Pract. 2005;54(3):231-9. 

10. Katon W, Sullivan M, Walker E. Medical symptoms without identified pathology: relationship to psychiatric disorders, childhood and adult trauma, and personality traits. Ann Intern Med. 2001;134(9):917-25.

11. Granot M, Yovell Y, Somer E, Beny A, Sadger R, Uliel-Mirkin R, et al. Trauma, attachment style, and somatization: a study of women with dyspareunia and women survivors of sexual abuse. BMC Womens Health. 2018;18(1):29. 

12. Hellström O. Allmänläkaren och den värdefulla vården. Läkartidningen. 2015;112:DMWI.

13. Johannisson K. Om begreppet kultursjukdom. Läkartidningen. 2008;105(44):3129-32. 

14. Presentation by a physician at Rehabkoordinatorutbildning. Region Skåne. 2012.

15. Lundin A, Sjöström C. Kroppssyndrom och relaterade syndrom. I:Herlofson J, Ekselius L, Lundin A, Mårtensson B, Åsberg M. Psykiatri. 2. Ed. Lund: Studentlitteratur; 2016. P. 411-41.

16. Laursen BS, Bajaj P, Olesen AS, Delmar C, Arendt-Nielsen L. Health related quality of life and quantitative pain measurement in females with chronic non-malignant pain. Eur J Pain. 2005;9(3):267-75. 

17. King CD, Jastrowski Mano KE, Barnett KA, Pfeiffer M, Ting TV. Pressure Pain Threshold and Anxiety in Adolescent Females With and Without Juvenile Fibromyalgia: A Pilot Study. Clin J Pain. 2017;33(7):620-26. 

18. Wolfe F, Smythe HA, Yunus MB, Bennett RM, Bombardier C, Goldenberg DL, et al. The American College of Rheumatology 1990 Criteria for the Classification of Fibromyalgia. Report of the Multicenter Criteria Committee. Arthritis Rheum. 1990;33(2):160-72. 

19. Blumenstiel K, Gerhardt A, Rolke R, Bieber C, Tesarz J, Friederich HC, et al. Quantitative Sensory Testing Profiles in Chronic Back Pain Are Distinct From Those in Fibromyalgia. Clin J Pain. 2011;27(8):682-90. 

20. Desmeules JA, Cedraschi C, Rapiti E, Baumgartner E, Finckh A, Cohen P, et al. Neurophysiologic evidence for a central sensitization in patients with fibromyalgia. Arthritis Rheum. 2003;48(5):1420-9. 

21. Peirs C, Williams SPG, Zhao X, Walsh CE, Gedeon JY, Cagle NE, et al. Dorsal Horn Circuits for Persistent Mechanical Pain. Neuron. 2015;87(4):797-812. 

22. Duan B, Cheng L, Bourane S, Britz O, Padilla C, Garcia-Campmany L, et al. Identification of Spinal Circuits Transmitting and Gating Mechanical Pain. Cell. 2014;159(6):1417-32. 

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