@gigiraj I've had these symptoms too, and my arm going entirely numb while I was sleeping on my side, and it was not the arm I was laying on. That was the first symptoms I noticed of Thoracic Outlet Syndrome which is a compression of the nerves and vessels that pass between the collar bone and rib cage as they go to the arm. When we sleep, often our arms are in a "raised" position which causes compression on an already tight area. It causes tinging, arm pain and feeling like I have tight rubber bands around my arms. My hands used to turn blue and cold. I am in physical therapy for this and have had the most success with myofascial release (MFR). Some of the tests for TOS involve listening to the pulse in the neck and raising the arm while turning the head, and the pulse stops. Mayo did doppler tests and also measured blood pressure changes in my fingers with tiny finger blood pressure cuffs. Posture is very important for TOS, and sleeping on your back can prevent arm pain because it helps keep the shoulders back. It gets to be like wearing a straight jacket when your neck and shoulders are tight. Neurologists can diagnose this. There is surgery for TOS, but it can cause scar tissue that makes a patient worse, and my doctor advised against it for me. Here is some information on TOS and our discussion with lots of information about MFR therapy.
https://www.mayoclinic.org/diseases-conditions/thoracic-outlet-syndrome/symptoms-causes/syc-20353988
https://connect.mayoclinic.org/discussion/myofascial-release-therapy-mfr-for-treating-compression-and-pain/
https://www.painscience.com/articles/respiration-connection.php
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3501918/
https://www.hindawi.com/journals/scientifica/2014/248163/
https://trainingandrehabilitation.com/how-truly-treat-thoracic-outlet-syndrome/
http://www.med.umich.edu/1libr/CVC/997ThoracicOutletSyndrome.pdf
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4129179/