Have you ever heard of carpal tunnel syndrome? Down syndrome? Chronic fatigue syndrome? The names may be familiar, but did you ever wonder why they are called "syndromes?" Some syndromes carry a descriptive name, as in restless legs syndrome, which is exactly what its name suggests. Others carry the name of a doctor or researcher associated with it, perhaps the person who first discovered it or the first to write about it in detail (as in the case of Down syndrome, named after Dr. John Langdon Down). These "syndromic" names provide a measure of validation — they sound more official, providing an air of legitimacy. If you were unlucky enough to have the condition, imagine the difference between telling your family and friends "I am always tired" and "I have been diagnosed with chronic fatigue syndrome." In some cases, however, the difference between calling an illness a syndrome and simply describing the symptoms is more about language than about science or medicine.
Usually, the term "syndrome" is used because there is no clear understanding of a disorder's cause — it often represents another example of the many ways the unknown and the poorly understood conditions acquire "official" names. A syndrome is simply a combination of features (symptoms, signs, and/or test results) that affected persons seem to share and that health-care providers or scientists find useful to consider as a group.
For Down syndrome, these features include short stature, reduced cognitive abilities, low set and small ears, and flattened facial features. Years after the detailed descriptions of Dr. Down appeared, the cause of the disorder was discovered — an extra chromosome #21 — so another, more specific name, Trisomy 21 (meaning that chromosome #21 has three copies instead of the normal two) may be a better name, but the names of illnesses, including the many syndromes, are difficult to change, even when something better comes along. Down syndrome and many other conditions whose cause was discovered later are still called by their original (and less useful) names — it is difficult to "unname" a condition.
Consider these other examples:
It may seem that calling diseases "syndromes" is more useful for the doctor than for the patients — after all, simply restating the problem ("restless legs") with the word "syndrome" on the end doesn't accomplish much on its own. Over time, it may even turn out that the "syndrome" is actually due to more than one disease. But, until that time, it may help the affected person to know that their condition is a recognized disorder, and that there are others with similar problems. In addition, researchers investigating the illness can use agreed-upon definitions of the syndrome, making it possible to conduct studies of comparable subjects. Finally, calling an illness a "syndrome" may not be ideal in all situations, but what is the alternative? When the only thing that links a group of patients is their combination of problems, calling it a syndrome is probably as good as any other approach.
If you or someone you care about has been diagnosed with a "syndrome," realize that it is no more and no less than an imprecise name for a combination of problems, lumped together for the sake of convenience and convention. More important than the name is knowing how it is likely to affect you over time and what you need to do to get better. Although many syndromes have names that have outlived their usefulness, it is useful to understand the limitations of what your doctor is saying.
Robert H. Shmerling, M.D., is associate physician at Beth Israel Deaconess Medical Center and associate professor at Harvard Medical School. He has been a practicing rheumatologist for over 20 years at Beth Israel Deaconess Medical Center. He is an active teacher in the Internal Medicine Residency Program, serving as the Robinson Firm Chief. He is also a teacher in the Rheumatology Fellowship Program.