Breath is the mirror of your emotions
Your breathing is a powerful index of your emotional state.
When we learnt about samkaras, we saw that the breath layer is where all our desire engrams are stored.
That is why we can never decide to stop breathing, because breathing is a basic survival instinct. It is much more powerful than our will.
We are alive because of our very desire to be alive!
This is the most basic desire in all living beings. All other desires are just different expressions of this primal desire.
Because our breathing itself is an expression of this desire energy, there is a close relationship between our desires and our breathing.
People whose personalities are dominated by rajas (restlessness), will usually have a rapid and heavy breathing pattern. Restlessness itself is the result of a deep dissatisfaction with the present moment. Such people will be carrying a lot of desires in their breath layer, and this affects their breathing pattern.
Not only for different individuals, even for the same person, the breathing pattern varies according to to the mood of the moment.
You may have seen that whenever you are in the grip of a powerful desire like lust, your breathing changes visibly.
If you look closely, even emotions like anger, fear and anxiety are indirect expressions of desire. Anger arises when a desire has been thwarted, and fear arises when there is the possibility of a desire not being fulfilled.
To cope with situations which are stressful, physically or mentally, we need an additional supply of life-energy. That is why the breath starts flowing rapidly at such times.
As you are, so you breathe!
Naturally, the reverse is also true.
By consciously altering the prana flow in the body, we can heal ourselves physically and mentally.