“Stress” is so abused and nebulous that it’s impossible to define. Nearly every condition is worsened by “stress” but there’s no way to measure it. And there’s no conclusive way to manage stress either. Medication, psychotropics, self medication, meditation. Nearly all of those are more broadly abused and yet stress “worsens”.
One person may run an intense soup kitchen 15 hours a day and feel little stress, and another can sit at a computer for 9 hours sending pointless emails and feel tremendous stress.
Fortunately, as you mention in your last sentence, stress is introspectable.
How exactly stress corresponds to biomarkers doesn’t matter if your desire is to lower it.
The issue is that many of us don’t pay attention to how we keep our body & mind throughout the day, or do so on a very superficial level. So strain on the body can accumulate for a long time.
“Stress management” is a lifetime skill. It doesn’t come in bulletpoints, it’s as broad as “living happily”.
Edit: That said, this can make the advice “be less stressed” a bit vacuous.
But people do get scared when random health issues flare up and become more conscious of how they deal with stress in life.
So it’s not bad to keep reminding people either :)
True that “sleep better, eat better, exercise” is generic advice ignoring constraints. Like telling someone with insomnia, three kids, and a night shift to “sleep better” or telling someone broke to “have more money.”
But being difficult to put into action doesn’t mean the advice is wrong. Sleep deprivation measurably increases cortisol and inflammatory markers. Exercise measurably reduces them. These actions have quantifiable sometimes immediate effects regardless of how we define stress.