Why Your Deep Breath
Might Be Making
Things Worse

Watch what happens when you ask someone to take a deep breath

They will almost certainly puff their chest out and raise their shoulders. This is the instinctive response — but it's the wrong one. By focusing on the upper chest, you're relying on the intercostal muscles, the small bands of muscle between the ribs, rather than the diaphragm, the dome-shaped muscle at the base of the ribcage that does most of the heavy lifting. The diaphragm is responsible for drawing in roughly 75% of the air we breathe. When we bypass it, we're operating at a fraction of our lung capacity while believing we're doing something helpful.

The second thing people tend to do is gasp — a sharp, fast inhalation that feels like a good lungful of air. It isn't. Repeated fast inhalations activate the sympathetic nervous system, the fight-or-flight response. Add upper chest breathing to a gasp, and you have a combination that can actively increase stress and anxiety rather than reduce it.

The cortisol problem

When the fight-or-flight system is triggered, cortisol is released into the bloodstream. Once it's there, it takes one to two hours to return to baseline levels. That's a long time, particularly if you're already anxious. And if your response to a cortisol spike is dysfunctional breathing — which it often is — you can end up in a repeating cycle where each attempt to calm yourself makes the underlying physiology worse.

The third common mistake is focusing on the inhalation. Inhalations stimulate the sympathetic nervous system. It's the exhalation that does the calming work. Long, slow exhales stimulate the vagus nerve — the main communication line of the parasympathetic nervous system — and trigger the release of neurotransmitters that reduce arousal and promote calm. If your deep breath is all inhale and no exhale, you're pulling on the accelerator when you need the brake.

What a useful deep breath actually looks like

If you want to help yourself or someone else who is stressed, here is what actually works. First, sit down if you can — this reduces the load on the diaphragm, which also has a secondary role stabilising the core. Then take a light, slow breath in through the nose. Not a gasp. Not a dramatic chest expansion. A quiet, gentle inhalation that lets the belly and lower ribs expand naturally as the diaphragm descends. Then exhale slowly through the nose — longer than the inhale. Repeat for at least a minute, longer if you can.

A useful hand placement: one hand on the belly, one on the chest. The goal is for the belly-hand to move and the chest-hand to stay relatively still. This isn't about forcing the belly out — it's a cue to shift attention away from the upper chest and invite the diaphragm to do its job. The movement of the belly is a consequence of functional breathing, not a technique in itself.

The longer-term benefit

Used once, this kind of breathing can take the edge off a stressful moment. Practised daily, it does something more important: it keeps your baseline cortisol levels lower over time, and it trains your parasympathetic nervous system to respond more quickly and effectively when stress does spike.

Most people who struggle with anxiety have a nervous system that has been running hot for a long time. Slow nasal breathing is one of the most direct ways to begin retraining it — not by avoiding stress, but by giving the body a more efficient way to process and recover from it.

The breath you take when you're anxious matters. But the breathing you practise every other moment matters more. That's where the real change happens.