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Research library · Mind & mood

Stress and your nervous system

Short bursts of stress make you sharper. Stress that never switches off raises blood pressure, inflammation and heart risk. Your breath is the fastest remote control you have over your nervous system.

Good evidenceUpdated Oct 2026 · 4 new studies
5 mina day of slow 'cyclic sighing' lifted mood more than mindfulness meditationBalban 2023, Cell Rep Med, 111 adults
1.6×heart attack and stroke risk per step up in stress-centre (amygdala) activity on brain scansTawakol 2017, Lancet, 293 adults
8 wkof mindfulness training worked as well as a common anxiety medicineHoge 2023, JAMA Psychiatry, 276 adults
01
The basics

Two pedals: accelerator and brake

Your autonomic nervous system runs in the background. The sympathetic side is the accelerator: fight or flight, faster heart, tense muscles, sugar released into the blood. The parasympathetic side, led by the vagus nerve, is the brake: rest, digest and repair.

When your brain senses a threat, a chain called the HPA axis releases cortisol. That's useful for a deadline or a sprint. The problem is when it never settles: months of high stress are linked to high blood pressure, belly fat, poor sleep, lower immunity and heart disease.

Breathing is the one part of this system you can steer directly. Breathing in speeds the heart slightly; a long, slow exhale slows it by activating the vagus nerve. That's why slow breathing calms you within minutes.

Cyclic sighing: the calming breath

Two inhales through the nose, then a long, slow exhale through the mouth. Heart rate rises a little on the way in and falls on the long way out.

LungsHeart rate Inhale+ top up Long exhale:vagus nerve slows the heart
02
How it works

How a stress response works

1

Threat spotted

The amygdala, your brain's alarm, reacts to danger, worry or pressure.

2

Alarm sounds

Adrenaline and cortisol are released within seconds to minutes.

3

Body revs up

Heart rate, blood pressure and blood sugar rise; digestion pauses.

4

Exhale switches it off

Slow breathing, movement and safety signals turn on the brake.

03
Measure it

How stressed are you?

  • Perceived Stress Scale (PSS-10): 10 questions about the last month. It's free online and widely used in research.
  • HRV and resting heart rate: a falling HRV and rising morning pulse over several days often reflect stress, not just training.
  • Body signs: clenched jaw, shallow breathing, poor sleep, gut upset, snapping at people.
  • When to get help: if stress stops you sleeping, working or enjoying things for more than two weeks, talk to a doctor.
Try your number14 PSS-10 score
LowModerateHigh
040

Perceived Stress Scale (Cohen 1983). Scores are a guide, not a diagnosis.

04
What the research says

The key studies

0.511.5 1 35–40 1.1 41–48 1.27 49–54 1.33 55+ Hours worked per week Stroke risk (1 = 35–40 hours)
Kivimäki 2015: pooled studies from Europe, the US and Australia.
2023Cell Reports Medicine

Balban et al.

111 adults, 1 month

Five minutes a day of cyclic sighing (two inhales, one long exhale) improved mood and lowered breathing rate more than mindfulness meditation.

Find on PubMed ↗
2017Lancet

Tawakol et al.

293 adults, brain scans

Higher resting activity in the amygdala predicted heart attacks and strokes over about 4 years, partly through bone-marrow activity and artery inflammation.

Find on PubMed ↗
2023JAMA Psychiatry

Hoge et al.

276 adults with anxiety

An 8-week mindfulness course reduced anxiety as much as the medicine escitalopram.

Find on PubMed ↗
2023Scientific Reports

Fincham et al.

12 trials, 785 adults

Breathwork lowered self-reported stress, anxiety and depression compared with control groups.

Find on PubMed ↗
2015Lancet

Kivimäki et al.

528,908 adults (stroke analysis)

Working 55+ hours a week was linked to a 33% higher risk of stroke compared with a standard week.

Find on PubMed ↗
05
New in 2025–26

What the newest research adds

Large 2025 trials show that 10 minutes a day of app-based meditation can cut stress meaningfully at work. But breathing techniques have only thin evidence so far, and meditation is not side-effect free for everyone.

The new studies, in order

Every study added to this page since January 2025. Green rings are the strongest evidence: large trials or meta-analyses.

Jan 2025Jul 2025Jan 2026Jul 2026 Now RadinJAMA Netw Open VanClin Psychol Sci MützeFront Psychiatry HirshbergJAMA Intern Med

Ten minutes a day, eight weeks

Radin et al., 2025, 1,458 hospital staff. Drop in perceived stress score after 8 weeks with a meditation app vs a waiting list.

−0−2−4−6 Drop in stress score (points) −1.45 Waiting list −5.84 Meditation app
NewJan 2025JAMA Netw Open

Radin et al.

1,458 hospital employees, 8 weeks plus 4-month follow-up

Ten minutes a day of app-guided meditation lowered stress scores by 5.8 points versus 1.5 points in the waiting-list group, a large effect that mostly lasted at 4 months. People who meditated 5 to 10 minutes a day gained more than those doing under 5.

Good evidenceRead the source ↗
NewAug 2025JAMA Intern Med

Hirshberg et al.

2,315 health workers in Mexico, 37 weeks

A 13-week remote well-being course with a free app reduced distress and burnout and raised well-being, and the benefit grew by 37 weeks. This was despite only about 1 in 4 people fully keeping up with it.

Good evidenceRead the source ↗
NewJul 2025Front Psychiatry

Mütze et al.

6 trials, 517 patients

Yoga breathing (pranayama) gave only a small drop in symptoms for people with mental health conditions, and no clear effect on depression. Most trials were low quality, and fast breathing styles caused more side effects, so breathing should not replace proven treatment.

Early evidenceRead the source ↗
New2025Clin Psychol Sci

Van Dam et al.

Nearly 900 US adults who meditate

About 30% of meditators reported a challenging or distressing experience, and 9% said it got in the way of daily life. Risk was higher for people already struggling with their mental health and for those on intensive retreats.

Good evidenceRead the source ↗
What this changes for you

Ten minutes a day of guided meditation is a well-tested way to lower stress. Slow breathing is fine as a calming tool, but the evidence for it treating anxiety or depression is thin. If meditation leaves you feeling worse, stop and talk to someone.

06
Take action

Daily ways to hit the brake

Small, repeatable habits work better than an occasional spa day.

  1. 1

    Two sighs, long exhale

    Breathe in through the nose, top up with a second short inhale, then exhale slowly through the mouth. Repeat for 5 minutes.

  2. 2

    Move it out

    A brisk 10–20 minute walk uses up stress hormones and lifts mood.

  3. 3

    Get outside

    Morning daylight and green space lower stress and help sleep.

  4. 4

    Talk it through

    Sharing a worry with someone you trust lowers the stress response.

  5. 5

    Set a stop time

    Fix a time each evening when work messages go off.

  6. 6

    Wind down

    A 30-minute screen-free routine before bed protects sleep, the base of stress resilience.

07
Myth or fact

Common myths, checked

✕ MythAll stress is bad.

✓ FactShort, manageable stress (exercise, a challenge) makes you stronger. The harm comes from stress that never lets up.

✕ MythVenting anger by hitting a pillow helps.

✓ FactStudies show it tends to increase anger and aggression. Slow breathing or moving works better.

✕ MythYou need an hour of meditation.

✓ FactFive minutes of slow breathing a day changed mood in a month-long trial.

✕ MythStress is all in your head.

✓ FactIt changes heart rate, blood pressure, blood sugar, immunity and digestion.

08
Questions

Frequently asked

What is the vagus nerve?

A long nerve from the brainstem to the heart, lungs and gut. It's the main 'brake' of your nervous system.

Box breathing or cyclic sighing?

Both help. In the 2023 trial, cyclic sighing, with its longer exhale, had the biggest effect on mood.

Does caffeine make stress worse?

It can raise heart rate and anxiety in sensitive people. Keep it before noon if you're stressed or sleeping badly.

09
Test yourself

True, partly true or myth?

Read each claim and pick an answer: the card flips to show the verdict and why. Not sure? Use “Just reveal”.

Score 0/0Streak 0Best 0
Card № 01True or myth?

Short-term stress can sharpen focus and performance.

True

Short-term stress can sharpen focus and performance.

Acute stress hormones help in the moment; the problem is stress that never switches off.

Card № 02True or myth?

Chronic stress is linked to higher blood pressure and heart disease.

True

Chronic stress is linked to higher blood pressure and heart disease.

The INTERHEART study found psychosocial stress raised heart attack risk about as much as high blood pressure.

Card № 03True or myth?

Stress is all in your head.

Myth

Stress is all in your head.

It changes heart rate, blood pressure, blood sugar, immunity and sleep through hormones and nerves.

Card № 04True or myth?

A long, slow exhale calms the nervous system.

True

A long, slow exhale calms the nervous system.

Breathing out activates the vagus nerve; the 'physiological sigh' (two inhales, long exhale) reduced stress in a 2023 trial.

Card № 05True or myth?

Exercise is a stress reliever.

Partly true

Exercise is a stress reliever.

Regular exercise lowers stress over time, but very hard training adds stress if you're already exhausted.

Card № 06True or myth?

Time in nature lowers stress.

True

Time in nature lowers stress.

About 2 hours a week in green space is linked to better wellbeing (White 2019, 20,000 people).

Card № 07True or myth?

Venting anger by hitting a pillow helps release stress.

Myth

Venting anger by hitting a pillow helps release stress.

A 2024 meta-analysis found venting doesn't reduce anger; calming activities do.

Card № 08True or myth?

Mindfulness programmes can reduce anxiety and stress.

True

Mindfulness programmes can reduce anxiety and stress.

Trials show modest benefits; an 8-week course was as effective as an anxiety drug in a 2022 trial (Hoge, JAMA Psychiatry).

Card № 09True or myth?

Cortisol is the bad stress hormone.

Partly true

Cortisol is the bad stress hormone.

Cortisol is essential: it wakes you up and controls inflammation. Problems come when it stays high for too long.

Card № 10True or myth?

Some people just thrive on constant stress.

Myth

Some people just thrive on constant stress.

Some cope better, but long-term high stress still affects the body, even if people feel fine.

10
Sources

References and related topics

  1. Balban et al. (2023). Cell Reports Medicine. 111 adults, 1 month. PubMed ↗
  2. Tawakol et al. (2017). Lancet. 293 adults, brain scans. PubMed ↗
  3. Hoge et al. (2023). JAMA Psychiatry. 276 adults with anxiety. PubMed ↗
  4. Fincham et al. (2023). Scientific Reports. 12 trials, 785 adults. PubMed ↗
  5. Kivimäki et al. (2015). Lancet. 528,908 adults (stroke analysis). PubMed ↗
  6. Radin et al. (2025). JAMA Netw Open. 1,458 hospital employees, 8 weeks plus 4-month follow-up. Source ↗
  7. Hirshberg et al. (2025). JAMA Intern Med. 2,315 health workers in Mexico, 37 weeks. Source ↗
  8. Mütze et al. (2025). Front Psychiatry. 6 trials, 517 patients. Source ↗
  9. Van Dam et al. (2025). Clin Psychol Sci. Nearly 900 US adults who meditate. Source ↗