Blood

• blood prevails in Macbeth
• it starts with the bloody battle between the Scots and the Norwegian intruders
• the wounded captain in Act 1, Scene 2 describes the ongoings with very gory details
• as Macbeth and his wife come to kill more and more innocents, blood starts to represent their guilt and they feel that the blood they have shed stains them and that they are not able to wash themselves off of it
• the guilt they feel in connection to the blood chases them into their grave

Weather

• weather is used as a way of predicting the future or as a way of foreshadowing the coming events
• thunder, lightning, rain and grave storms are indicators of the turbulent circumstances in Scotland
• bad things always happen when bad weather occurs:
  
  • the witches always meet in storms
  • bad things always happen in the dark, evil things at night (Duncan is murdered in his sleep, Banquo shortly after sunset)
  • battles happen in daylight as they are for the good of Scotland

Sleep

• sleep actually symbolizes innocence, peace of mind or purity
• by killing Duncan in his sleep, Macbeth murders sleep: he also hears a voice saying "Macbeth does murder sleep" (Act 2, Scene 2)
• this manifests in Lady Macbeth‘s beginning to sleepwalk and in Macbeth being haunted by his nightmares
• as Macbeth violates the code of a noble warrior (you cannot murder someone who is defenceless, as Duncan is in his sleep), he suffers from insomnia and gains a heat-oppressed brain
• sleepwalking was regarded as a sign of a person who has sinned morally: Lady Macbeth reveals her vulnerability and her being guilt-possessed as she sleepwalks