There are two major perspectives of madness that can be seen in Macbeth. First, we see Macbeth "going mad" at the dinner party after he commissions the death of Banquo (Act III). We understand that he is seeing Banquo's ghost at the dinner table, unaware that others cannot also see the ghost. Such an apparition speaks to madness. In this case, madness in being related to guilt. In Act V, the same connection between madness and guilt is seen in Lady Macbeth. Sleep walking and pretending to wash her hands, the audience again understands that Lady Macbeth has gone mad with the guilt of Duncan's murder. In her case, the madness climaxes when Lady Macbeth takes her own life.
We see a different type of madness in Macbeth in Act V. He has a false sense of security in the Apparitions' prophecies, and he has gone mad over power. He wants more and more power.This time, his madness takes the form of recklessness as he charges into battle. He causally challenges men on the battlefield, and insults his own men for their alarm at the advancing army. His greediness for power has made him mad.