When a person is in a state of tension for a long time, the sympathetic nervous system is continuously activated, and the body mistakenly believes it is always in "fight or flight" mode. As a result, blood vessels constrict, blood pressure rises, stress hormones (especially cortisol) remain elevated for a long time, the endocrine system is disrupted, and fat distribution and metabolism change. Over time, this is not just "feeling tired," but structural changes at the body level: some people become thin and age faster, some experience edema and dull skin. The changes you see on the outside are essentially the result of long-term physiological stress.