Macbeth is not literally cursed by a spell, but he brings a kind of “curse” on himself through his own ambition, his choices, and his reliance on the witches.
The witches spark the process by giving prophecies that tempt Macbeth with power, but they never force him to act. Instead, they use half-truths that lure him into trusting them. As Banquo warns, such “instruments of darkness” tell small truths only to lead people toward ruin. Once Macbeth chooses to believe them and act—by murdering Duncan—he sets off a chain reaction he can’t escape.
From that moment on, Macbeth’s life begins to feel cursed because every violent act demands another. After killing Duncan, he is immediately haunted by guilt, hearing voices and losing the ability to sleep. Later, he admits he is “in blood / Stepp’d in so far” that turning back is as hard as continuing forward. What looks like a curse is really the psychological and moral trap created by his own actions: violence leads to more violence, and guilt leads to paranoia and madness. The witches deepen this sense of doom by giving him misleading assurances, like the claim that “no man that’s born of woman” can harm him. Macbeth treats these as guarantees of safety, which makes him reckless and overconfident. In reality, their words are designed to “draw him on to his confusion,” giving him false security until the truth destroys him.
Leading up to his own death, Macbeth is isolated, feared, and emotionally numb. Everything he gained through ambition has turned hollow. His fate is a direct result of his own decision to pursue power at any cost, and so the play suggests that the real curse is unchecked ambition itself.