Carlos Solis
You overslept, you’re rushing, you glance at your phone—and irritation hits. Your body flips the same switches that once helped people run from danger or fight predators. That reaction helps in short bursts, but it can harm you when the body stays in that mode.
“The fastest reaction in a stressful situation is an adrenaline surge that raises heart rate, blood pressure, and breathing,” explains Professor Kavita Vedhara, a stress and behavioral medicine specialist at Cardiff University. It’s the fight-or-flight response, which primes the body to act instantly.
About 30 minutes after the initial reaction, cortisol levels rise in the blood. “Cortisol helps regulate blood pressure, suppress inflammation, and increase blood glucose so you have energy,” Vedhara says. Those functions once saved lives; today the same mechanisms trigger in response to social or information stressors (for example, arguments or hurtful comments).
When the body mobilizes resources for fight or flight, it temporarily deprioritizes other processes—digestion, tissue repair, and the immune response. One-off responses are fine, but if stress is constant, the body never catches up on postponed tasks.
How Chronic Stress Hurts Your Health
The best-known consequence of chronic stress is a weakened immune system. Weaker immunity raises the risk of infections, reduces vaccine effectiveness, and slows wound healing. Research also links long-term stress to higher rates of obesity, depression, and the progression of neurodegenerative diseases such as Alzheimer’s.
Because stress physiology is complex, we often notice a range of bodily changes. That can alarm people: why is the heart racing? People start tracking normal bodily fluctuations closely. That attention amplifies sensations and adds another layer of anxiety.
Stress also makes us hypervigilant and prone to interpret ordinary body sensations as threats. Stress hormones and ancient survival circuits in the brain also impair decision-making—we may act impulsively or avoid useful actions (for example, not leaving the house because we feel unsafe).
How Much Stress Is Too Much?
Science hasn’t pinned down an exact threshold. “The stress-response system is flexible: it needs to respond and then recover,” Vedhara says. Prolonged, constant stress can cause real harm, but how much damage it does depends on the duration and intensity of the load.
Life circumstances matter. In a classic 1990s study, researchers exposed nearly 400 healthy volunteers to a cold virus and found a strong link between stress level and the chance of getting sick. For older adults, whose immune systems already work less efficiently, chronic stress can have more noticeable effects.
Individual differences also matter: past trauma, life experience, and self-regulation skills determine a person’s sensitivity to stress.
What Actually Helps
The simplest, best-supported strategies are controlled breathing and physical activity. When people feel anxious, they breathe shallowly and quickly, which feeds the threat response. Slow breathing signals the brain that you’re safe and activates a relaxation response.
But when stress is prolonged and draining, one deep breath won’t fix things. In those cases, evidence-based psychological approaches such as cognitive behavioral therapy (CBT) work. CBT helps identify automatic catastrophic thoughts (“I can’t cope”), gather realistic evidence against those beliefs, and change harmful coping behaviors (for example, drinking too much).
Mindfulness programs work differently: they teach people to step back from intrusive thoughts rather than argue with them. It’s often useful to try both approaches—CBT to break destructive thought patterns and mindfulness to accept stressors you can’t change.
Practical Tips
- Catch your reaction early: slow your breathing or take a short walk to blunt a stress spike.
- Move regularly: exercise to burn off excess adrenaline and lift your mood.
- Rethink harmful coping: working overtime or avoiding problems usually makes stress worse.
- Reach out for support: talk with loved ones—social connections soften long-term effects.
- Get professional help: seek support if stress dominates most of your days or you’re worried about your mental health.
You can’t always avoid the “mammoths” charging at you, but you can control how you react.
Based on reporting in The Guardian
