This illustrates that Macbeth is feeling guilt towards the death of Duncan. Only because he can not agree with what people have to say, because he regrets his actions, and feels guilty for what he has done.
At the start of the play, the character is described as a hero, and Shakespeare persuades us that the qualities which made Macbeth heroic are still present, even in the king's darkest moments.
Her attitude reflects ambition, strength of will, cruelty, and dissimulation. She writes a letter, but the reader does not know what the letter says.
This blood is from the killings she has taken part in, and it shows that the guilt can not be easily rid of, but will stick with her for a long time.
For example, Macbeth is visited by the ghost of Banquo, whom he murdered to protect his secret. The guilt Macbeth feels softens the character, which allows him to appear at least slightly sympathetic to the audience. Thus, the effects can be very diverse. Another vivid imagery which is effectively used throughout the play to develop the theme of guilt and conscience is the reoccurring image of troubled sleep.
Guilt may cause a person to have trouble sleeping and difficulty in relationships with others. I have thee not, and yet I see thee still. After Macbeth is promised greatness by three witches on a heath, Macbeth and Lady Macbeth try to achieve his prophecy.