Blood is everywhere in Macbeth, beginning with the opening battle between the Scots and the Norwegian invaders, which is described in harrowing terms by the wounded captain in Act 1, Scene 2. Once Macbeth and Lady Macbeth embark upon their murderous journey, blood comes to symbolize their guilt, and they begin to feel that their crimes have stained them in a way that cannot be washed clean. Read more...
As in other Shakespearean tragedies, Macbeth’s grotesque murder spree is accompanied by a number of unnatural occurrences in the natural realm. From the thunder and lightning that accompany the witches’ appearances to the terrible storms that rage on the night of Duncan’s murder, these violations of the natural order reflect corruption in the moral and political orders. Taken from Sparksnotes