“Stress or tension, however,
has its origin in the attitudes to our actions.
There are two attitudes in particular that are the cause of stress.
These are:
Aham and Mama.
Aham or Ahaṃkāra is the attitude “I am the doer”
and Mama or Mamakara is the attitude “it is for me”.
These two factors most surely produce Udvega.
The moment the attitude is one of Na–Mama
– ‘not by me’, ‘not for me’,  there cannot be any stress.
A person who has total faith in God cannot
have stress and will not exhibit the Udvega.”
–  Yoga Sūtra on Stress – An interview with TKV Desikachar