A health risk is any situation, substance, or behaviour that threatens human health — from the microbial hazards of unsafe food handling to the chronic risks of smoking, excess alcohol, or a poor diet. Risk assessment weighs two factors: how likely the harm is, and how severe. Food businesses live by this calculus — identifying where pathogens, allergens, or chemicals could harm consumers and controlling those points. Public health extends it to populations: the health risks of obesity, air pollution, or antimicrobial resistance. Communicating risk honestly — neither minimising nor scaremongering — is among the hardest tasks in health, since people weigh familiar, voluntary risks very differently from unfamiliar, imposed ones.