Positives:

Excellent for spine and neck comfort.
Effective against insomnia.
Reduces headaches.
Helps reduce acid reflux.
Prevents facial wrinkles and skin cracks.
cons:

It may worsen snoring in individuals with sleep apnea.
Improper position of the arms can cause pressure on the shoulder nerve.
Possibility of lower back pain.
Solution:

Sleep without a pillow to maintain normal alignment of the head, neck and spine.

3. Record the situation
   Lying on your side with your arms down defines your torso position, which is especially preferable when you’re on your left side.