Can you collapse while in a lying position?

This is really a question related to semantics rather than medical terminology. Anyway, I wanted to know how it is called when e.g. A person is lying on the bed and does something, such as texting on the iPhone or reading a book, and just all of a sudden he/ she faints and drops his/ her arms down, as well as whatever he/ she was holding. Would it be correct to say that the person collapsed after fainting, even though he/ she was in a lying position? Or does the fainting make you collapse only when you were previously standing, sitting, kneeling, crouching, or whatever?

Consider "passed out." It is impossible to conceive how one can collapse from a lying or prone position.

No, collapse means falling down.

No, the word literally means 'falling'.
You can faint, or pass out, or lose consciousness, or have a stroke.

You are confusing when "collapse" is used informally, instead of "faint", rather than the literal meaning, which is fall down.

Benjamin Disraeli asked, "Is man Ape or Angel?" We can collapse physically or psychologically, and even lying in bed is not a state of either. If a mother is told while lying in bed her child suddenly died she will certainly collapse both physically and psychologically.