In Shakespeare's "Macbeth," the quote reflects the deep pain that remains unexpressed within a troubled soul. It suggests that when individuals suffer and do not voice their grief, the burden of their emotions can become overwhelming, leading to a sense of despair. The heart that is stressed by this unvoiced sorrow is at risk of breaking under the weight of its anguish.

The line captures the essence of human suffering, emphasizing the importance of communication in the healing process. When grief is left unarticulated, it can fester and escalate, resulting in mental and emotional turmoil. Shakespeare's insight into the human condition demonstrates that sharing one's burdens is crucial to prevent an inner implosion.