In Hamlet, corruption pervades the state of Denmark, symbolizing moral decay and the disintegration of social and political order. Shakespeare uses vivid imagery of disease and decay to illustrate the pervasive corruption, which is rooted in Claudius's usurpation of the throne and his incestuous marriage to Gertrude. This theme is woven throughout the play, highlighting the destructive impact of corruption on individuals and the kingdom.

Shakespeare frequently employs disease imagery to convey Denmark's moral corruption. Hamlet describes the air as "a foul and pestilent congregation of vapours," suggesting the pervasive nature of the corruption. The imagery of ulcers, pustules, and other ailments underscores the idea of a nation in decline. Even virtue is not immune, as Hamlet notes, "Virtue itself 'scapes not calumnious strokes: The canker galls the infants of the spring, Too oft before their buttons be disclosed." This imagery extends to mental illness, as Hamlet's "wit’s diseased" reflects the psychological toll of the corruption.

Claudius and Gertrude are central to the corruption in Denmark. Claudius's murder of King Hamlet and his subsequent marriage to Gertrude establish a corrupt regime. Claudius's deceitful nature and schemes to eliminate Hamlet further entrench the kingdom's moral decay. Gertrude's complicity, seen in her lack of remorse and willingness to spy on Hamlet, exacerbates the corruption. Together, they create an environment that Hamlet likens to a prison, with their actions contributing to the kingdom's "rotten" state.

The theme of corruption is also evident in the interactions between characters. Laertes's warning to Ophelia about Hamlet reveals the hypocrisy and authority within the court. His speech, echoing his father Polonius's authoritative tone, highlights the "something rotten" in Denmark. Ophelia's response, "Do not, as some ungracious pastors do, Show me the steep and thorny way to heaven," exposes the duplicity in Laertes's advice, further illustrating the pervasive corruption.

Shakespeare underscores the theme of corruption and decay to emphasize the gravity of Claudius's crime and its impact on Denmark. From Horatio's assertion that something is "rotten in the state of Denmark" to Hamlet's reflections on Yorick's skull, the play is steeped in imagery of decay. This theme highlights the moral disintegration at Denmark's core and Hamlet's obsession with mortality. Through this pervasive theme, Shakespeare illustrates the destructive power of corruption on both the state and the individual.