How can stress affect physical health?

Good and bad: Lots of goofy stuff is written about "the harmful effects of stress" to sell things. "eustress" prompts you to learn new skills, do things you need to do, achieve. "distress" is when you're really helpless, being mistreated and can't escape -- sometimes this seems to precipitate illness though it's hard to show; "major life events" haven't held up as preceding the onset of illness.

Stress & Health: Stress can affect physical health by raising blood pressure; interfering with sleep; increasing inflammatory responses in the body; increasing cortisol; disrupting eating patterns and leading to weight gain & diabetes; causing muscle tension & pain; causing digestive problems and GI distress; leading to chest pain & breathing problems -- even asthmatic attacks in susceptible people. And more.