The Nocebo Effect is a phenomenon where a person experiences negative side effects or symptoms after believing they will, even if they receive a harmless treatment. This can happen when someone is told about potential side effects of a medication, leading them to feel those effects without any actual cause. It highlights the power of the mind in influencing physical health. For example, if a patient takes a sugar pill but is informed that it might cause headaches, they might start to feel pain simply because they expect it. This effect shows how our beliefs and expectations can significantly impact our well-being, similar to the more widely known Placebo Effect.