1. A thumb rule
The primary objective of sleep is to rest your body. So a thumb rule would be that the position in which your body will feel most relaxed is the best sleeping position. The most comfortable position may vary according to each person’s condition and current state. The position in which you should sleep is in your control only until you fall asleep.
2. Analysis of various positions of sleep
There are three possible positions of sleep. Their analysis is as follows.
2 A. Sleeping on the stomach (prone)
Sleeping on the stomach puts more stress on the spinal cord than any other position. If newborns, infants, and toddlers likely to suffocate if they sleep on their stomach. Therefore, they should be made to sleep on their back.
2 B. Sleeping on the back (supine)
If we consider that there is a 100% pressure on our spinal cord while standing, this pressure reduces by 75% when we sleep in the supine position. Since sleeping on the back puts minimum pressure on our spinal cord, those who have issues related to spinal cord benefit from sleeping supine. If we place a small pillow under our knees while sleeping on the back, the spinal cord gets even more relaxed.
2B. 1. Relation between sleeping on the back and snoring
Those who have a habit of snoring, their snoring increases if they sleep on their back. Snoring begins when air finds it difficult to move through the nose and mouth due to the loosened inner muscles of the throat. Sleeping on the back increases the risk of this obstruction in the respiratory tract. When we sleep on the side, the loosened inner skin of the throat moves away from the respiratory tract and therefore the snoring stops. Hence many people experience that when they sleep on the side, their snoring gets reduced.
2 C. Side sleeping
Sleeping on one’s side exerts 75% pressure on the spinal cord when compared to standing. Sleeping on the right side activates Chandranadi and sleeping on the left side activates Suryanadi.
प्राक्शिरा दक्षिणाननो दक्षिणशिराः प्रागाननो वा स्वपेत् ।
prākshirā dakshiṇānano dakshiṇashirāḥ prāgānano vā svapet ।
– Acharendu, Shayanvidhiprayog
Meaning : One should orient one’s head towards east or south while sleeping on the side.
Since our scriptures recommend sleeping on one side, unless there is a need to sleep in a specific position due to certain conditions, side sleeping is most appropriate.
प्राक्शिरः शयने विद्यात् धनम् आयुश्च दक्षिणे ।
पश्चिमे प्रबला चिन्ता हानिमृत्युरथोत्तरे ।।
prākshiraḥ shayane vidyāt dhanam āyushca dakshiṇe ।
pashcime prabalā cintā hānimṛtyurathottare ।।
Meaning : By orienting our head towards east while sleeping, we acquire wealth and by orienting our head towards south, we acquire long life. Orienting our head towards west while sleeping increases our worries and orienting it towards north while sleeping invites ill-effects or death.
2C 1. Process that occurs due to side sleeping
When we sleep on the side, the nostril which is on the lower side gets gradually blocked. When it gets obstructed to a particular limit, we change our side. Then gradually that nostril opens and the other nostril which is now on the lower side starts getting blocked. Since alternate nostrils get blocked, we keep changing the side after specific time while sleeping.
2 D. Benefits of changing position when asleep
We spend one-fourth of the time every day sleeping. If we remain in one position for such a long duration everyday it can cause bedsores. If our position keeps changing when we are asleep, pressure does not get created only on one part of the body for a long time.’