Stress is a normal, healthy reaction to your body being under strain. When your body senses danger, it triggers a fight-or-flight reaction to help you defend yourself. This can include an elevated heart rate, deeper and faster breaths, shutting down unnecessary systems (like your digestive system) and sweating – all responses designed to help your body face the threat. There's nothing harmful in short-term stress; it can help you in a tricky situation and keeps your brain active. But when stress becomes long-term and consistent, it can put serious pressure on your body.