Where did the phrase "I need to get something off my chest" orginate?

Here is one person’s theory:

“From the eighteenth century on, writers and especially poets have talked about duties, delays, other negative things as “weighing” upon people or their spirits. The case of the weight upon the chest is interesting, as references to body parts often have a physiological basis. Having “a lump in your throat” is an example on one which has been elucidated as a feeling which results from s specific chemical change in the body. Having something weighing on the chest almost invariably accompanies nightmares (although the converse is not necessarily true—nightmares do not always occur if something weighs on your chest). ”

Source

I guess it means something deep inside your heart is bothering you.

Picked this from phrases.org.uk.

The Oxford English Dictionary defines the phrase, “get something off one’s chest,” as meaning “to relieve one’s mind by making a statement or confession,” and cites as its earliest example “1902 Daily Chron. 27 Sept. 3/2 The desire is either to deliver a message to the world or to express the individual personality—to ‘get it off your chest’ is the horrid, vulgar phrase.”

Although one need not concur in the characterization as a “horrid, vulgar phrase,” it’s true that it can refer either to something you feel you need to say because it needs saying, or to something you need to say because it has been “weighing on your conscience.”

Be that as it may, my recent experience with depression has given the phrase new meaning for me. One of my symptoms was this sense of pressure on my chest—as if a real weight were there. My heart felt pressed down and it was harder to breathe.

Getting that weight off my chest was incredibly relieving. It cleared up my chest, making me feel lighter.

It used to be that there was a form of punishment where a platform was placed on a person’s chest and things were then piled on top to make it heavier and heavier. The victim would have a harder and harder time breathing, and finally would suffocate. I imagine that being rescued at the last moment would be a literal getting of things off that person’s chest.

@wundayatta Cool. We have a new meaning for the phrase! :)

But the punishment thing, me not buying it!