In the Rheum where it happens

“A Trip to the Moon” (“Le Voyage dans la Lune”) is a 1902 French adventure short film directed by Georges Méliès

What IS rheumatology, anyway? I had to look it up.

I knew from Shakespeare that rheum was the term used back then for the fluid that tears and snot and sputum are made of.

...the north-east wind, 

Which then blew bitterly against our faces, 

Awaked the sleeping rheum, and so by chance  

Did grace our hollow parting with a tear.’

—Duke of Aumerle, “Richard II”

Why holds thine eye that lamentable rheum, 

Like a proud river peering o'er his bounds? 

—Constance, “King John” 

Therefore the moon, the governess of floods, 

Pale in her anger, washes all the air, 

That rheumatic diseases do abound: 

—Titania, “Midsummer Night’s Dream” 

And even way before Shakespeare: the prefix rheuma, meaning “to flow,” was apparently first used by a Greek physician 2000 years ago to refer to the phlegm that flows from the nose when a person is ill. So the word has been around a long time—but the word rheumatology didn’t come to be associated with the field until the mid-20th century.

Here's one of the best explanations I’ve come across (a rheumatologist trying to explain what he does):

As I see it, rheumatology is the study of inflammation (swelling, redness, warmth, and pain) occurring in the structures that hold up the body, such as the bones, muscles, and joints. Arthritis, or inflammation of the joints, is the most common disease that we see, both in children and adults (kids get arthritis too!). Arthritis comes in a variety of flavors, including juvenile, rheumatic, psoriatic, gouty, osteoarthritis, etc..

We also take care of complex diseases such as systemic lupus erythematosus, systemic sclerosis,  and dermatomyositis, in which the immune system attacks various different organs.  Vasculitis, or inflammation of a blood vessel, is another disease which we treat. Other strange illnesses (with even stranger names) such as Kawasaki disease, Sjögren syndrome, and relapsing polychondritis are all within the field of rheumatology.

Most of the above-mentioned diseases are considered autoimmune, in which the immune system loses the ability to recognize self from non-self.  When a cell of the immune system passes through the kidney, it should be able to recognize it and say: “Hello! You are my kidney, I will protect you against infections!” However, in autoimmune diseases, the immune cell gets confused and says: “Whoa! What is this bean-shaped organ doing here?You look foreign, I will fight you to the death!” As a result, the immune cell begins a process of inflammation that causes organ damage. Many different organs can be affected in autoimmune diseases, and the name of the disease depends on which organ is affected.