“Depending on whether the mind is in a state of Samādhi or not,
the person enjoys permanent happiness or
successive chains of unhappiness and happiness.
Those who accept nothing short of Samādhi,
freedom from the suffering of disease is realised.
After all, the root cause of disease is the disturbed mind,
when we cannot distinguish right from wrong or good from bad.”
– T Krishnamacharya on Yoga Sūtra Chapter One verse 34

“From this, the role of senses and sense objects
in causing a ground for disease becomes evident.
They are chiefly responsible for creating disturbance in the mind.
Hence the value of Vairāgya insisted as an aid to help the student.
Otherwise the whole system is sure to reach a state of chaos
because of the erratic movement of vital energy all over the body.
To put it another way, disease results from excess of contact
with objects not conducive to the individual system.”
– T Krishnamacharya on Yoga Sūtra Chapter One verse 34