In Macbeth what does mean when he says has murdered sleep?

When Macbeth says "Sleep no more! / Macbeth does murder sleep," he refers to the fact that he has killed King Duncan and, as a result, has lost the ability to sleep because he is haunted by guilt and remorse. He is saying that he has destroyed sleep, which is an essential part of human existence, and thus has condemned himself to a life of torment and unrest.