Breathing is usually an automated process, controlled by our autonomic nervous system - this involves balancing the sympathetic (fight or flight) system and the parasympathetic (rest and digest)
How we breathe is influenced by our environment and activity - exercise, stress, sleep etc
The trigger for breath is carbon dioxide levels in the blood (byproduct of cell metabolism), which controls blood pH levels. When we breathe out we release carbon dioxide, which alters pH - we breathe faster if more co2 is produced (ie running or illness) and slower if metabolism slows down.
Normally pH levels are tightly controlled as a change in these can be lethal (ie acidosis) .
We also breathe in oxygen which is essential for life, however this isn't actually the main driver of breath as many people think!
Stress also makes us breathe fast and shallow, in response to the sympathetic nervous system - this can create a feedback loop where we habitually start to breathe this way, in turn creating more stress
Over time breathing this way can cause muscle tension, headaches, back and neck issues, high blood pressure, palpitations and anxiety
The symptoms from panic attacks are partly due to hyperventilating (tingling fingers and lips and dizziness are signs of low co2) which creates further hyperventilation due to worsening anxiety
Learning to breathe slowly and deeply using conscious control is highly effective at reducing stress and improving health- intentionally activating the parasympathetic system, which slows down breathing and switches off the stress response
Having a longer exhale than inhale also stimulates the vagus nerve
Doing this through the nose creates a deeper breath, it also increases nitrous oxide levels - a beneficial chemical that lowers blood pressure, protects the heart and improves circulation (I'll do a separate post on this soon)
Pranayama is the term for breath in yoga. Tai chi, Buddhist chanting, and meditation all also use breathwork
Breathwork can be an incredibly powerful, simple and free strategy to reduce stress and improve health