Pain Threshold Versus Pain Tolerance and Fibromyalgia

There is a huge misconception that still exists when it comes to understanding the degree of pain people with Fibromyalgia experience. The reason for this confusion is that there are actually two separate terms used to describe levels of pain. The term “pain threshold” defines the level at which the body first perceives a stimuli as being painful. The term “pain tolerance” has a completely different meaning and basically defines how much pain a person can actually take without breaking. We can think of tolerance as the “acceptance level” of an existing pain.

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regulatepainPeople that suffer with Fibromyalgia have a low threshold and most often a very high tolerance to pain. This is partly true because they have been found to have greatly increased levels of substance P in the cerebral spinal fluid. Substance P is a neuromodulator (a substance that changes neurotransmitter effectiveness) that allows us to perceive a stimulus as painful. It is interesting to mention that there are actually some rare medical conditions where substance P is very low or completely absent and a person feels little or no pain. That may initially seem like a blessing but actually it can be very dangerous because there is then no “warning pain” when a critical condition requiring treatment exists in the body. Can you imagine how serious it would be for someone with acute appendicitis to not feel any pain and have the appendix rupture?

Obviously having a normal level of substance P is the ideal situation where your body tells you exactly what it should be feeling and pain is perceived at the appropriate level. Take a look at the illustration below and you will get a general idea how Substance P works. You can see that the transmission of nerve impulses and pain is quite intricate and involves many more chemicals but Substance P plays a very important role.

Now with elevation of Substance P, as in Fibromyalgia, a sensation that should be perceived as normal is felt as painful. The term for this condition of increased pain perception is hypergesia. Sometimes even a light touch on the skin can feel like burning and I have seen many patients that can’t even stand to have the bed sheets touch their legs at night. In Fibro patients a relatively minor muscle strain due to over exertion will often cause a totally inappropriate severe level of pain and then cause unnecessary muscle splinting and spasm which then has a downward spiraling effect. The body over responds due to an inaccurate pain signal caused by high substance P and starts what I call the “cascading of symptoms”. One simple strain becomes a serious of pains that can sometimes throw the Fibro patient into a severe flare.

supportgroupsSo does this mean that Fibro patients are weak? Does it mean that we are just being hysterical with the pain and over reacting? No, actually it is usually the complete opposite. Here is where the definitions of threshold vs. tolerance become very important. Fibro patients do feel pain sooner and at inappropriate levels but, for most of us, we have incredibly high pain tolerances. The reason for this is because Fibro patients deal with some level of pain all the time. I guess you can say that we grow more accustomed to living with pain. Most Fibro patients that I counsel and treat have a remarkable way of dealing with levels of pain that would drive a “NON Fibro” person absolutely insane. This is one of the main reasons that it makes me frustrated when I hear people that obviously do not understand Fibromyalgia say that Fibro patients are just being weak or wimpy. Considering what level of pain Fibro patients need to deal with, it is surely one of the worst things you can say to them. If those accusers ever woke up in a Fibro body for even 1 day, they would likely run to the ER or beg their doctor for some heavy duty narcotics. The thing is this: Fibro people have grown accustomed to living and dealing with pain and most often accept the lower to moderate levels in silence. That is where the high tolerance comes in to play. I often tell people that we look at most of our pain like we would view “elevator music”. It just is a low level background noise and we learn how to still have a life and accept or even ignore it. Usually it is just the severe flares that make most Fibro patients really complain but at that level the pain can be completely intrusive and there is no way one can ignore it.

It would really make things a whole lot easier if the people around us that do not have Fibromyalgia could understand the difference between the two terms threshold and tolerance. Most Fibro patients are not looking for sympathy; they are just seeking understanding. I have personally observed the supreme importance of a good support system in all of my Fibro patients. You can’t expect true support unless the ones that are most important to us understand that we are coming from a position of strength, not weakness.