Yoga Sutras of Patanjali translated by Yogi Kalinath - Chapter 1, Verse 31
Pada 1, Sutra 31
They (the distractions / the blocks / the obstacles) have the accompanying disruptions of pain, depression, tremor/restlessness of the body and irregular breathing.
In the previous verse Rishi Patanjali enumerated the distractions / blocks / obstacles of the mind that interfere with it turning inwards to uncover Truth. In this verse, he indicates a number of symptoms that are generated as a result of these distractions of the mind.
An unaware and undisciplined mind, an unruly mind creates pain or anxiety which in turn can lead to a state of depression when the individual feels incapacitated and incapable of dealing with his/her own inner conflicts. Due to the mind and body being one unit (as from a yoga perspective, the body is an extension of the mind: the mind is the subtle body while the physical self is the gross body), this can lead to a psychosomatic response (and dis-order by the mind being disorderly) such as tremors / restlessness of the body and
irregular breathing (anxiety can often trigger very shallow and rapid breathing, as the psyche and therefore soma think it is (irrationally) in danger).
This is why it is so important to get one’s house in order (i.e. one’s mind primarily and one’s life to follow) before attempting Sadhana proper. Someone who is earnest on the Path will encounter both Bliss and Despondency as part of the spiritual maturing process. One must push on no matter what, keeping the goal (Moksha) in mind while at the same time maintaining awareness that the journey is integral to the goal.