Helps bile flow more freely
The Lymph Drains toward the Left
Interestingly, the left side of the body is the dominant lymphatic side. Seventy-five percent of the body’s lymph fluid drains into the thoracic duct, which drains into the left side of the heart, left internal jugular vein, and left subclavian vein. (3) Along the way, lymph fluid carrying proteins, glucose, other metabolites, and waste products is cleansed and then drained into the left side of the heart.
This is why it is common in Ayurveda to deduce that left side ailments may be due to chronic lymphatic congestion. When the lymphatic system congests, it is more likely that lymph will back up on the left, more lymph-dominant side of the body. While this is not always the case, you can see the Ayurvedic logic at play here.
In the same non-scientific vein, issues that show up on the right side are thought to be due to imbalances in the liver and blood. Since the liver is on the right side of the body, liver congestion will more easily back up into the right side of the body and potentially cause problems.
The Priority System of the Body
According to Ayurveda, congestion happens in the body according to a certain pattern, or priority system. In this priority system, the lymph is the body’s first detox system to congest, before the liver and blood become overwhelmed.
Thus, early lymph issues may present more on the left side of the body and move to the right as they become more long-standing and begin to congest the liver and the blood, at which point symptoms may start to show up on the right side of the body.
Please read more about lymph-related issues in the Lymphatic Health category of my article library.
The Magic of Sleeping on the Left Side
The small intestine dumps waste through the ileocecal valve (ICV) on the right side of the body into the beginning of the large intestine. The large intestine travels up the right side of the belly across the tummy, where it dumps waste into the descending colon on the left side.
Sleeping on the left side allows gravity to encourage the food waste to move more easily from the small intestine into the large intestine through the ICV.
As the night wears on and you continue to sleep on your left side, the waste moves more easily into the descending colon. With the help of gravity and a good night’s sleep on the left side, the descending colon is full of waste and ready to easily and completely eliminate in the morning.
Better Heart Function
Of course, one of the biggest players on the left side is the heart. It makes sense that if you sleep on your left side, the lymph drainage toward the heart will, again, be helped by gravity, taking some of the workload off of the heart as you sleep.
The aorta, the biggest artery in the body, leaves the top of the heart and arches to the left before it heads down into the abdomen. By sleeping on the left side, the heart is pumping its biggest payload downhill into the descending aorta.
Sleeping on the left also allows much of the intestines to hang away from the very thin-walled inferior vena cava (IVC), which brings venous blood back toward the heart. Interestingly, the IVC lies against the right side of the spine, so when you lie on the left, much of the viscera falls away from the IVC. Here again, gravity is just making the heart’s job a little easier.
The Spleen Is On the Left
The spleen, which is part of the lymphatic system, is also on the left. The spleen is much like a gigantic lymph node, except that in addition to filtering lymph, it also filters blood. When you lay on the left side, drainage back to the spleen is once again helped and made easier by gravity.
Remember, the lymph system drains all the cells in the body via movement and muscular contractions, rather than being pumped by the heart. Helping the lymph to drain to the spleen and heart with gravity is a good thing!
Ever Feel Sleepy After a Big Meal?
A common practice in Ayurveda is to rest on the left side after a meal. Unlike a siesta, where the whole afternoon is taken off, Ayurveda suggests a short, 10-minute rest on the left side to help the body properly digest the food.
The stomach and the pancreas (which make digestive enzymes) hang like slings on the left side. When you lie on the left side, the stomach and pancreas hang naturally, allowing for optimal and efficient digestion. The food is encouraged to move through the stomach naturally and the pancreatic enzymes are released as needed, rather than all at once, which might happen more easily than if you were on the right side with the pull of gravity.
If you lie on the right side, the stomach and pancreas will hang in a somewhat unnatural position, forcing them to empty their contents prematurely.
Meanwhile, the liver and gallbladder hang on the right side. Resting on the left side allows them to hang freely and secrete precious bile, with the help of gravity, into the digestive tract to emulsify fats and neutralize the acids of the stomach.
When the digestive process is encouraged in this way, it can often be a smoother and ultimately shorter digestive cycle that doesn’t leave you feeling sapped throughout the entire afternoon. By taking a short rest on the left side, you may actually save yourself from more fatigue throughout the day!