Final answer:
Lady Macbeth becomes a sleepwalker as a result of her overwhelming guilt and psychological turmoil in Shakespeare's Macbeth.
Step-by-step explanation:
In William Shakespeare's Macbeth, Lady Macbeth suffers from a profound psychological turmoil following her involvement in the murder of King Duncan. The distress manifests in her sleep, where she becomes a sleepwalker. Her nighttime wandering is a physical symptom of the guilt and mental anguish that haunt her, a stark contrast to the earlier bravado where she convinces Macbeth to follow through with their dark plans. By the play's end, Lady Macbeth's inability to escape her guilt even in rest, which was once seen as 'the balm of hurt minds,' symbolizes her complete mental breakdown.