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What Is Functio Laesa?

A. Leverkuhn
A. Leverkuhn

Functio laesa is a classical Latin term for a loss of function in part of the body. This term is attributed to Galen, in that fifth century scientist’s enumeration of, “five signs of inflammation” It is used for referring to some effects of inflammation or other conditions in various medical scenarios.

In addition to functio laesa, four other classical effects of inflammation are written in Latin as tumor, rubor, calor and dolor. Tumor is a neoplasm or cyst. Rubor refers to the reddening of skin in the affected area. Calor refers to fever, and dolor is the Latin for pain, another common sign of different kinds of inflammation.

Some doctors classify loss of consciousness as functio laesa.
Some doctors classify loss of consciousness as functio laesa.

In some cases, doctors may refer to top-level nervous system reactions as functio laesa, where the loss of consciousness or nerve sensation could be classified in this way. Doctors might refer to this response as “eclipsing” another of these classic symptoms: pain. Other examples of functio laesa regard a more limited loss of function.

As a general and top-level symptom of conditions, functio laesa could indicate a wide range of illnesses. These would include some types of viruses, as well as bacterial infections. In general, the characteristic of functio laesa as it is most probably applied can be used extensively in different kinds of diagnosis.

It’s important to note that many in the medical profession still consider the term indicative of a much more classic and antiquated system of diagnosis. Other alternative systems are more frequently in use in modern medicine, where instead of observing a list of physical symptoms, doctors do tests of bodily tissues or blood in order to ascertain what is wrong with a patient. Understanding how diagnostic tools like the five signs of inflammation have been used throughout the centuries is beneficial to a medical student, but as modern medicine has reached far beyond the boundaries of what was known at the time the list was adopted, these items should be understood in the context of a much more detailed medical analysis.

One way that functio laesa has always helped medical workers is in determining the extent of a condition. More minor conditions may start with several of the other classic elements of inflammation. As the condition progresses, and functio laesa sets in, doctors can evaluate the extent of the condition in order to treat it effectively. This is in all likelihood one of the most frequent uses of this medical term over time.

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Discussion Comments


@burcidi-- No, not all of the five symptoms have to be there together for there to be inflammation. Some might not be there. For example, arthritis is inflammation but it is usually not accompanied by swelling, redness and functio laesa.

You're also right that function doesn't have to be lost entirely for there to be functio laesa. It could just mean that the function is hindered or that it's not functioning normally.


I want to go to Medical School when I finish High School and I'm taking some health courses at a community college right now. We read about inflammation a couple of weeks ago so I found this article really interesting and helpful.

I have a question- do we need to have all five signs listed for it to be inflammation? Is it enough to have functio laesa, and pain for example?

I've sprained my ankle and I can't walk on it properly because it hurts a lot. Does this mean it is inflammation?

I know if I go to the doctor, they would take an x-ray to find out if it's inflammation or not, but I don't think that's necessary. Hopefully it will go away in a few days.

By the way, I'm using functio laesa here because my foot's function is inhibited, not entirely lost. That's correct, right?


Is the term "functio laesa" ever used to refer to organ failure?

I think this must be the most serious type of loss of function because it could result in death. I have an uncle who had kidney failure due to inflammation and fattening of his liver. He received a liver transplant and thankfully is doing fine now.

For a while though we were not sure he would make it because the body cannot continue functioning without a liver. The same is true for all other organs when there isn't a backup organ like the kidneys or the lungs.

Health is the best thing in the world. All cases of functio laesa must be difficult for patients, but organ failure is more complicated and dangerous in my view.

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    • Some doctors classify loss of consciousness as functio laesa.
      Some doctors classify loss of consciousness as functio laesa.