Stress, blood pressure and blood sugar: what the data show

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7 min read

The short answer

Stress hormones raise blood pressure and blood sugar for a while each time they surge. In large studies of workers, chronic stress at work was linked with a modestly higher risk over the years: about 11 to 15 percent higher for type 2 diabetes and about 23 percent higher for heart disease. Relaxation methods such as breathing exercises, meditation and mindfulness lowered systolic blood pressure, the top number, by about 7 to 10 points in short trials compared with no treatment. The certainty of that evidence is very low, the effect seems to fade, and in mindfulness trials that checked, it did not clearly show up in readings taken outside the clinic. Mindfulness programs lowered A1c, a measure of average blood sugar over about three months, by less than half a percentage point, with low certainty. For blood pressure, regular physical activity has stronger evidence than any relaxation method.

What stress does in the moment

When you are under pressure, your body releases adrenaline and cortisol. Adrenaline raises your heart rate and blood pressure. Both hormones move stored glucose and fat into the blood, which gives muscles fuel in an emergency.

In healthy volunteers, researchers infused adrenaline, cortisol and a third hormone, glucagon, at levels meant to mimic severe stress. Together they pushed blood sugar above 200 mg/dL. A normal fasting level is below 100. Each hormone alone produced only a mild or brief rise. Blood pressure also rises during a short burst of stress and then comes back down. A review of 14 studies found no consistent evidence that brief stress leads to lasting high blood pressure, and chronic stress was more often linked with it.

What chronic stress does over years

Some of the largest long-term studies of stress have looked at job strain, meaning jobs with high demands and little control. In 124,808 working adults in five European countries followed for about 10 years, people with job strain were 15 percent more likely to develop type 2 diabetes. After accounting for lifestyle habits, the difference was 11 percent, a borderline result. For context, about 3 in 1,000 workers in the study developed diabetes each year.

In 197,473 workers in seven European countries followed for about seven and a half years, job strain was linked with a 23 percent higher risk of coronary heart disease, the narrowing of the heart's arteries that leads to most heart attacks. The researchers estimated that, if job strain causes heart disease, it would account for about 3.4 percent of these cases. They wrote that tackling standard risk factors such as smoking would have a much larger effect.

Stress also works through habits. It can change what people eat, how much they move and whether they take their medicines. In people with diabetes, it can also affect how closely they follow their treatment and meal plans. Each of those affects blood pressure and blood sugar.

What lowers blood pressure

A 2025 review of 182 studies, most in people with high blood pressure, compared relaxation methods with no treatment, a waiting list or usual care. In people with high blood pressure, breathing exercises, meditation, mindfulness, tai chi and yoga, music, muscle relaxation and talking therapy each lowered systolic blood pressure by about 7 to 10 points. The reviewers rated the certainty of that evidence as very low, few studies followed people for more than three months, and the effect seemed to fade over time. In the two studies of people whose blood pressure was only mildly raised, the effects were small.

Clinic readings can overstate the benefit. The standard eight-week mindfulness course lowered clinic systolic blood pressure by about 7 points in a pooled analysis of 12 trials, only one of which was rated high quality, but it did not significantly lower readings taken outside the clinic. Breathing devices sold for blood pressure did no better than a fake device or music in blinded trials, where people did not know which one they had.

For comparison, one blood pressure medicine at a standard dose lowers systolic pressure by about 9 points more than a dummy pill. That figure comes from blinded trials against a placebo, a stricter test than the comparisons with no treatment behind the relaxation figures, so the two numbers are not directly comparable. Regular aerobic exercise lowers systolic pressure by about 8 points in people with high blood pressure.

The 2025 US blood pressure guideline from the American Heart Association and the American College of Cardiology recommends more physical activity, including aerobic exercise, at its strongest grade. It says stress reduction through transcendental meditation, breathing techniques or yoga may be reasonable as an addition to lifestyle changes or medicine, a weaker grade. A 2017 American Heart Association statement on meditation called it low in cost and low in risk, with benefits that remain to be better established.

What lowers blood sugar

A 2025 review looked at 31 trials of mindfulness programs in adults with type 2 diabetes. Nine trials with 734 people measured A1c against usual care or a waiting list. At the end of the program, A1c was 0.44 percentage points lower in the mindfulness groups, with low certainty. A few months later, the difference was uncertain. Evidence of very low certainty suggested that adding mindfulness to a lifestyle program did not lower A1c further. A separate review of the standard eight-week mindfulness course in people with diabetes found no detectable effect on A1c, although the course did ease anxiety and depression.

Stress management after a heart diagnosis

One trial tested stress management in 151 people with coronary heart disease in North Carolina. All took part in 12 weeks of cardiac rehabilitation, a supervised exercise and education program, and about half also attended stress management training. Stress scores fell more in that group. Over a typical follow-up of about three years, 18 percent of the stress management group had a serious event such as death, a heart attack, a stroke or a procedure to reopen an artery, compared with 33 percent of the group that had rehabilitation alone. These events were not the main question the trial was designed to answer, and the trial was small.

What you can do

Put regular physical activity first. For blood pressure it has stronger evidence than any relaxation method, and in people with high blood pressure, aerobic exercise lowers the top number by about 8 points.
If a relaxation practice such as slow breathing, meditation, mindfulness, tai chi or yoga helps you feel calmer, keep it. Meditation is low in cost and low in risk. Use these practices as an addition to the rest of your plan.
Judge any practice by your home readings. Clinic readings can overstate the effect, so check whether your home blood pressure changes.
Skip devices sold to guide your breathing. In blinded trials they did no better than a fake device or music.
Watch what stress does to your habits: food choices, skipped activity and missed doses. Those changes affect blood pressure and blood sugar too.

Never start, stop, or change the dose of any prescription medication without consulting your physician.

References

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Reviews how stress responses and stress-related habits may contribute to type 2 diabetes, drawing on animal, epidemiological and laboratory studies. Narrative review.
Shamoon H, Hendler R, Sherwin RS. J Clin Endocrinol Metab. 1981;52(6):1235-1241. https://doi.org/10.1210/jcem-52-6-1235
In healthy fasting volunteers, adrenaline, glucagon and cortisol infused together at severe-stress levels raised blood sugar above 200 mg/dL, while each alone caused a mild or brief rise. Experimental physiology study.
Sparrenberger F, et al. J Hum Hypertens. 2009;23(1):12-19. https://doi.org/10.1038/jhh.2008.74
Across 14 observational studies, there was no consistent evidence that acute stress leads to lasting high blood pressure, while chronic stress was more often linked with it. Observational, systematic review.
Nyberg ST, et al. Diabetes Care. 2014;37(8):2268-2275. https://doi.org/10.2337/dc13-2936
In 124,808 European workers followed for about 10 years, job strain was linked with a 15 percent higher risk of type 2 diabetes, or 11 percent after adjustment for lifestyle. Observational, pooled analysis.
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In 197,473 European workers followed for about 7.5 years, job strain was linked with a 23 percent higher risk of coronary heart disease and, assuming a causal link, would account for about 3.4 percent of cases. Observational, pooled analysis.
Marcovecchio ML, Chiarelli F. Sci Signal. 2012;5(247):pt10. https://doi.org/10.1126/scisignal.2003508
Describes direct effects of stress hormones on blood sugar in diabetes and indirect effects through treatment, monitoring, meal and exercise habits. Narrative review.
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Across 182 studies, relaxation and stress management methods lowered systolic pressure by about 7 to 10 points versus passive comparisons in people with high blood pressure, with very low certainty and effects that faded. Randomized trials, network meta-analysis.
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Across 12 trials, mindfulness-based stress reduction lowered clinic blood pressure by 6.64/2.47 points but did not significantly lower out-of-office readings. Randomized trials, meta-analysis.
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In blinded trials, device-guided breathing did not lower office blood pressure compared with a sham procedure or music. Randomized trials, individual patient data meta-analysis.
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Across 354 double-blind, placebo-controlled trials, one blood pressure medicine at standard dose lowered pressure by an average of 9.1/5.5 points. Randomized trials, meta-analysis.
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In people with high blood pressure, endurance exercise training lowered blood pressure by about 8.3/5.2 points. Randomized trials, meta-analysis.
Jones DW, et al. Hypertension. 2025;82(10):e212-e316. https://doi.org/10.1161/HYP.0000000000000249
The 2025 AHA/ACC high blood pressure guideline. Recommends increased physical activity, including aerobic exercise, and rates stress reduction through transcendental meditation, breathing techniques or yoga as may be reasonable, as an adjunct. Clinical guideline.
Levine GN, et al. J Am Heart Assoc. 2017;6(10):e002218. https://doi.org/10.1161/JAHA.117.002218
States that, given its low cost and low risk, meditation may be considered as an adjunct to standard cardiovascular risk reduction, with benefits that remain to be better established. Scientific statement.
Ee CC, et al. Integr Med Res. 2025;14(2):101138. https://doi.org/10.1016/j.imr.2025.101138
In adults with type 2 diabetes, mindfulness programs lowered A1c by 0.44 percentage points at the end of treatment versus usual care or a waiting list, with low certainty, and, with very low certainty, added no A1c benefit to lifestyle programs. Randomized trials, meta-analysis.
Fisher V, Li WW, Malabu U. Appl Psychol Health Well Being. 2023;15(4):1733-1749. https://doi.org/10.1111/aphw.12441
In people with diabetes, mindfulness-based stress reduction eased anxiety and depression but showed no detectable effect on A1c. Randomized trials, meta-analysis.
Blumenthal JA, et al. Circulation. 2016;133(14):1341-1350. https://doi.org/10.1161/CIRCULATIONAHA.115.018926
In 151 people with coronary heart disease, adding stress management training to cardiac rehabilitation lowered stress scores; fewer had clinical events over about three years (18 versus 33 percent, a secondary outcome). Randomized trial.

One study explained in plain language every week, with sources attached, plus the free metabolic health guide: https://guides.selfprinciple.org/metabolic

This content is for educational purposes only and is not medical advice. Always consult your healthcare provider for individual care. The views expressed are Dr. Sean Hashmi's own and do not represent his employer.