“I'm managing” is one of the least informative sentences in the language. It reports a self-assessment — and self-assessment turns out to be a poor guide to what stress is actually doing.
There is a more literal measurement, studied for three decades under the name allostatic load.
What it is
Allostatic load is the cumulative physiological cost of adapting to stress, described in the literature as the “wear and tear” on the brain and body. The point is that adapting is not free. The systems that help you cope carry a running cost, and the bill accumulates whether or not you feel it.
It is measured unromantically, through a panel of biological markers: systolic and diastolic blood pressure, waist-to-hip ratio, BMI, HDL cholesterol, the total-cholesterol-to-HDL ratio, triglycerides, HbA1c, C-reactive protein and cortisol.
Notice what is absent from that list. There is no question about how stressed you feel.
What the recent research shows
Higher allostatic load is associated with poorer outcomes across immune, cardiovascular and metabolic function.
A study in the Journal of the American Heart Association found higher allostatic load associated with up to a 21% higher risk of major cardiac events within two years among patients diagnosed with breast, lung or colorectal cancer.
2025 work also found associations between cumulative physiological stress and brain structure in older adults — though the authors themselves describe that study as exploratory, which is the right word for it.
And a large analysis using the All of Us Research Program examined the relationship between perceived stress — how stressed people say they are — and measured allostatic load. That the question needs asking at all tells you something. The felt experience and the physiological cost are related, but they are not the same measurement.
The practical implication
If the load accumulates independently of whether you notice it, then two common conclusions become unreliable.
The first is I've adapted, so I'm fine. Adaptation is the mechanism that produces the load. Getting used to something is not the same as it costing less.
The second is the opposite error: I feel terrible, therefore something is physiologically wrong. Feeling depleted is real and worth attending to, but it is not itself a measurement.
The useful move is unglamorous. Most of that marker panel appears on a standard blood test and a blood-pressure cuff. If you have been running hot for years, that is a more informative conversation with a doctor than an inventory of how tired you feel.
A limit worth naming
Allostatic load is a research construct, not a clinical diagnosis. There is no single agreed formula — different studies use different marker sets and different cut-offs, which is precisely why 2025 papers are still proposing new ways to measure it. It is a way of thinking about cumulative cost, not a number you can be assigned.
It also sits inside circumstances. Much of this literature concerns populations under sustained social and economic pressure, where the load is a product of conditions rather than choices. Framing that as a personal-management problem would be both inaccurate and unkind.
If someone measured what the last five years had cost you, rather than asking how you were coping, what do you think they would find?
The research referred to here
- Allostatic load / chronic stress and cardiovascular outcomes in patients diagnosed with breast, lung, or colorectal cancer (Journal of the American Heart Association)
- Perceived stress and allostatic load: results from the All of Us Research Program
- Allostatic load, a measure of cumulative physiological stress, impairs brain structure but not β-accumulation in older adults (Frontiers in Aging Neuroscience, 2025)