Is Alzheimer disease an illness or a syndrome? Can a flu be referred to as a disorder? There is an abundance of medical terms to describe illness: while some overlap, others exist for a reason.
Our first semantic stop is the word injury, which is quite distinct from the rest of the medical grab-bag. An injury results in physical harm or damage to the body. For example, a cut is an injury. Fractures and dislocations would also fall under that category. It may seem overly simplistic: indeed, one could explore this definition further and write an entire article about it. For our purposes, we will stick to “physical damage”.
A disease by comparison is a condition that impairs normal function. It can result from various causes, such as environmental or genetic, and is characterized by a group of symptoms that point to its cause. For example, celiac disease is a condition that impairs the normal function of the small intestine. It is caused by the inappropriate response of a person’s immune system to gluten, a protein found in certain cereals such as wheat. It can result in the following symptoms: diarrhea, weight loss, anemia, osteoporosis, headaches, and fatigue, among others.
So is celiac disease also a disorder? The word “disorder” is often used as a more neutral replacement for “disease” which has, over the years, accumulated a, shall we say, negative aura. It sounds more respectful to talk of someone having a disorder than a disease, as the latter brings to mind images of contagion and putrefaction. Morbidity is similarly synonymous. If “disease” leaves a vulgar taste in the mouth, and if “disorder” sounds a little too sterile, “morbidity” is the aristocratic brother, commonly used by health care professionals to discuss amongst themselves. The word “comorbidity” simply means the presence of more than one disease in a single individual. For instance, a patient with diabetes and pneumonia would be said to have “comorbidities”.
So what is an illness? The illness is typically what is felt by the patient. While the underlying flu disease would be the presence of the influenza virus in the upper respiratory tract, the illness is the congestion, runny nose, cough, and fatigue that are felt by the patient following his or her immune response to the virus. One can be ill without an underlying disease; one can also be diseased without being ill.
An infection involves an invasion by an organism of a host, i.e. you. Viruses, bacteria, fungi, and parasites can infect the human body and lead to an infectious disease.
Finally, the trickiest of them all may be syndrome. An etymological check on the name, however, is quite helpful. The word is made up of two Greek roots: syn- and -dromos. Syn- means “with”, as in “synthetic”, which means “put together”. -dromos signifies “running” or “course”, as in the words “velodrome” and “hippodrome”. Thus “syndrome” means “that which runs together”.
A syndrome is a group of signs and symptoms that always appear together. For instance, cri du chat syndrome is characterized by a peculiar mewing cry in infants, associated with mental retardation and abnormal facial features such as low-set ears and small head size. If a paediatrician notices the cat-like cry of the baby, he or she can look for other signs and symptoms to help confirm the diagnosis. The definitive diagnosis these days will come in the form of a genetic test which will confirm the absence of a piece of chromosome 5, the cause of this syndrome.
And here’s a bonus definition to end on: man flu. A “man flu” is a terrible infectious disease, caused by a particularly nasty strain of the influenza virus, a mega-influenzanodon, if you will, which selectively invades the entire body of XY-chromosome carriers. It is characterized by extreme fatigue, unending mucus production in the nose, acute throat pain, and a pressing medical need for bedsheets and movies about giant robots fighting each other. The medical establishment shies away from treating it: even doctors know their limits.
(Feature picture by Laura Smith)