the/a/no article in names of diseases

I didn’t want to hijack this thread, but it raised another question I’ve wondered about for decades. (Okay, not for every moment of the last 30 years or so, but it comes to mind occasionally.)

Some diseases/disorders get no article; some get a “the,” and some get an “a/an.”


The flu
The plague
The mumps
The vapors

A cold
A headache (tooth ache, stomach ache; an earache)
A nervous breakdown

Is there some pattern to this?

You’ll usually find that the ones with articles of some sort are common names, not the actual medical names. I’ve heard people talking about “the AIDS” and “the apnea”, diseases that don’t normally take the article even in common speech.

The flu is influenza, medically. Likewise, doctors talk about either bubonic (or pneumonic) plague, or name the particular organism. The vapors isn’t even a real disorder, just a common (and antiquated) term for feeling faint. A cold is a rhinovirus or an upper respiratory infection. A nervous breakdown isn’t a valid psychiatric diagnosis, I don’t think. I’d imagine there’s a more specific name for it within the profession.

Pretty much what was said there, plus that around here, it’s only ever plain “mumps”.