Answer:
Their guilt is manifested by hallucinations that leave them disturbed and unable to sleep.
Step-by-step explanation:
One of Shakespeare's so-called Great Tragedies (alongside Hamlet, Othello, King Lear, and Antony and Cleopatra), the play Macbeth is considered a work on ambition, betrayal, and guilt. The assassination committed by Macbeth and Lady Macbeth takes a predominant proportion in the work with respect to the feeling of guilt since those who have no feelings - a sociopath, a psychopath - will not suffer from the outcome of their actions. Macbeth and Lady Macbeth were brought to a level of mental and spiritual wear that only truly human humans could feel.
Because of their guilt, Macbeth and Lady Macbeth are constantly plagued with hallucinations that leave them so disturbed and worn out that they cannot sleep.