The nervous system

Modern science offers another lens through which to understand this relationship: the nervous system. At every moment, the nervous system is quietly asking a question: am I safe, or do I need to prepare for something?

When it perceives challenge, uncertainty, pressure, or threat, the body prepares itself for action. Heart rate increases. Muscles become alert. Breathing becomes quicker and shallower. Attention narrows. This response is what we commonly call stress.