In Proverbs 17 in the Bible, what is it that "does good like a medicine"?

In Proverbs 17, it is a merry heart that "does good like a medicine."

The wording comes from Proverbs 17:22 in the King James Version: "A merry heart doeth good like a medicine: but a broken spirit drieth the bones." In this proverb, the heart refers to a person’s inner disposition, emotions, and outlook—not merely the physical organ. The verse contrasts joyful well-being with the draining effects of despair.

Many modern translations use expressions such as "a cheerful heart," "a joyful heart," or "a happy heart." Those renderings can make the answer appear different, but they translate the same central idea. Because the question quotes the traditional wording, "A Merry Heart" is the single canonical answer.

The verse is often quoted as a general saying about happiness and health. Its original context is wisdom literature, where Proverbs uses vivid contrasts to describe how character and emotional state affect a person’s life. The phrase should not be read as a guarantee that cheerfulness cures every illness; it is poetic wisdom about the restorative value of joy.