The position in which you spend the night can have a greater impact on your body than you think. The elderly have always said: if your stomach hurts, turn to your left side and it will feel better. Today, more and more research agrees with them. Sleeping on the left side is not just a comfortable habit, but it has been proven to support the heart, digestion, detoxification, and even help with nighttime heartburn.

Why the left side?

The human body appears symmetrical at first glance: two arms, two legs, two lung lobes. But organs are not arranged evenly. The liver is on the right, the heart is slightly tilted to the left, and the stomach and pancreas are also positioned more towards the left. This asymmetry is the reason why the sleeping position can greatly impact our health.

A 2020 study by the National Sleep Foundation showed that over 74% of people sleep either on their side or back, with a small percentage sleeping on their stomach. Those who slept on the left side reported fewer digestive issues, less frequent heartburn, and even better daytime well-being.

Now, let's see why.

1. Sleeping on the left side aids in body detoxification
   
   Our body has a special system of tubes and nodes called the lymphatic system. If you imagine it, it's like a drainage channel that removes toxins, bacteria, and other waste. When you sleep on the left side, gravity helps these tubes to flow more easily towards the central collection point, which speeds up the elimination of toxins from the body.
   
   If the lymphatic system gets clogged, it can lead to fatigue, muscle aches, headaches, and even joint inflammations. This is why traditional Indian medicine Ayurveda has been recommending sleeping on the left side for centuries. Modern data confirms this: a 2021 study published in the Journal of Clinical Medicine found that people who sleep on their left side reported 30% fewer symptoms of chronic fatigue.
   
   
2. The left side supports the healthy function of the spleen
   
   You might have heard of the spleen but not exactly sure what it does. The spleen is an organ that cleanses the blood, removes old blood cells and bacteria. It is located on the left side of the body, so sleeping on the left side relieves and promotes its natural flow.
   
   Imagine pouring water down a slope - on the left side, gravity literally helps the blood flow more easily into the spleen where it is filtered. This results in cleaner blood and a stronger immune system. In a 2023 study of 500 adults in Europe, those who more frequently slept on the left side showed better immune response test results, as the spleen was more effective in performing its function.
   
   
3. The heart works easier when you sleep on the left side
   
   The heart is one of the most important organs. It beats around 100,000 times a day and pumps about 7,500 liters of blood. Most of the heart is inclined to the left, so the body's position during sleep is crucial.
   
   When you sleep on the left side, the heart works with the help of gravity and consumes less energy. This means less pressure on the heart muscle and a calmer heart rate. In contrast, sleeping on the right side requires more effort as the blood needs to flow against gravity.
   
   A 2020 study published in the American Journal of Cardiology found that sleeping on the left side is associated with lower blood pressure in people over 45 years old. This is particularly important as 35% of adults in Europe have high blood pressure issues.
   
   
4. The left side relieves the liver
   
   The liver is our largest detoxification organ and has over 500 different functions, from cleansing the blood to metabolizing food. It is situated on the right side of the body. Sleeping on the right side puts pressure on the liver, which can strain it.
   
   Sleeping on the left side gives the liver space to function properly. According to Ayurvedic practices, this prevents the accumulation of fat in the liver and even reduces the risk of high cholesterol. Similar results are confirmed by modern science: a 2022 study in India showed that regular left-sided sleeping is linked to a lower likelihood of fatty liver, which is one of the fastest-growing health issues today.
   
   
5. Improved digestion flows naturally
   
   The stomach and pancreas, where digestive juices are produced, are positioned on the left side. When you sleep on the left side, gravity helps food to move slowly through the stomach and digest at its own pace.
   
   If you sleep on the right side, food often moves too quickly, and the juices do not have enough time to do their job. The result can be bloating, poorer digestion, and sometimes even pain.
   
   A study conducted in Japan in 2020 among 200 people with stomach issues found that 63% of those who attempted sleeping on their left side reported significant improvement within two weeks.
   
   
6. The intestines cleanse more easily at night
   
   At the juncture of the small and large intestines, we have a "valve" that acts as a gate for waste. It is located on the left side of the lower abdomen. When you sleep on the left side, gravity once again plays a role. Waste naturally moves through the colon, aiding easier morning movements.
   
   It is no coincidence that people who sleep on the left side often report regular bowel movements. Healthy digestion is the foundation of well-being, as studies show that irregular bowel movements affect 20% of adults in Europe. Sleeping on the left side can be the cheapest and most natural solution to this common problem.
   
   
7. Sleeping on the left side reduces heartburn
   
   Heartburn is one of the most common issues of modern times, affecting 30% of people at least once a month. It is an uncomfortable sensation when stomach acid refluxes back into the esophagus.
   
   A 2021 study published in the Journal of Gastroenterology clearly showed that sleeping on the right side is linked to more frequent heartburn, while sleeping on the left side reduces symptoms by half. This is because in this position, stomach acid struggles to travel back to the esophagus.

What does folk wisdom say?

In folk medicine, it has always been emphasized that sleeping on the left side soothes the stomach and heart. Our grandparents in the countryside said that the body "cleanses more easily" when you sleep on the left side. Today, science only confirms these pieces of advice that have been passed down from generation to generation.

How to easily adopt this habit?

If you are accustomed to sleeping on the right side, the change might not be easy at first. But simple tricks can help: you can place a small pillow by your side to keep you on the left side. If you sleep on your side, placing a pillow between your legs can further relieve your spine and hips.

In a 2025 study in Germany, 48% of people who tried switching to sleeping on their left side reported that this simple change improved their sleep quality in just one month.

An affordable and natural solution for better health

Sleeping on the left side is one of the cheapest natural practices for better well-being. It does not require special medications, expensive therapies, or complex habits - just a decision to try sleeping differently.

Your heart, digestion, liver, and even spleen will be grateful. If you add regular exercise and a healthy diet to this, just by changing your sleeping position, you can do a lot for your health.

So, we invite you to try it today: lay on your left side and listen to your body. You might feel the difference as soon as tomorrow.