Exact passages might include the doctor saying: "A great perturbation in nature, to recieve at once the benefit of sleep and do the effects of watching" (10-12). The doctor is responding to the gentlwoman's concern about Lady Macbeth sleepwalking. "Perturbation" indicates that the doctor suggests something psychological rather than pathological (a disease) is troubling Lady Macbeth. A second passage is Lady Macbeth saying, "Out, damned spot! Out, I say! One: two: why, then 'tis time to do 't. Hell is murky" (38-39). Here Lady Macbeth is trying to wash the blood from her hands, the guilt from her soul, for murdering Duncan. The spot is a symbol of her psychological state, her guilt." A third passage is another interpretation by the doctor of Lady Macbeth's mental state. He says "This disease isbeyond my practice" and then "Unnatural deeds /Do breed unnatural troubles. Infected minds / To their deaf pillows will discharge their secrets" (62, 75-78). He says this again to the Gentlewoman after Lady Macbeth goes back to bed ("To bed, to bed, to bed!") after sleepwalking and sleeptalking
Lady Macbeth, we find out from her chambermaid, insists always to have a light with her. Light and dark are major thematic elements in Macbeth, so Lady M's insistence indicates that she wants light to replace the dark elements that she invoked back in Act 1. Lady M also mentions, in this scene, the murder of Macduff's wife and family. All of these things she seemingly does with no consciousness, as if she is doing them in her sleep.
Lady Macbeth has been sleepwalking as a manifestation of her guilt. She acts out pieces of her crime in these episodes.
On one occasion, she rises, goes to the closet, and reads, writes, and refolds a sheet of paper, before returning it to the closet and going to bed.
Another instance, she continually rubs her hands together and cries about how the "spots" will not leave her hands.
She also relives the night of Duncan's murder, speaking to her husband as if he were there.