In Macbeth, both the main characters Macbeth and Lady Macbeth begin to show clear signs of madness through alterations in their physical senses.(smell, sight etc.) this is evident when Lady Macbeth hallucinates that her hands are still covered in king Duncan’s blood despite having washed then several times.
Here’s the smell of blood still: all the perfumes of Arabia will not sweeten this little hand. (Act 5, scene 1, 46-47)
Shakespeare uses imagery to give a better understanding of what is going on within the characters mind. Here madness is altering Lady Macbeth’s sense of smell and sight, this tricks her into believing that King Duncan’s blood will never dissipate from her hands even though they are perfectly clean. Another example of the theme of madness that is characterized by Macbeth is found in act three, scene four, the climax of the play. Immediately guilt ridden from ordering the murder of Banquo, Macbeth reaches his pinnacle of madness; exemplified by his delusion of Banquo's ghost. Showing that he can no longer differentiate between reality and his imagination Macbeth shouts,
Avaunt!
Cited: Shakespeare, William. King Lear. New York: Washington Press, 1992 Shakespeare, William. Macbeth. New York: Washington Press, 1992