This can lead to discomfort such as:
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Shoulder soreness
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Hip tenderness
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Arm numbness
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Neck stiffness
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Lower-back discomfort
The solution is not necessarily to stop side sleeping.
A supportive mattress that allows the shoulder and hip to settle comfortably may help. The pillow should also be high enough to keep the neck aligned with the rest of the spine.
People with existing shoulder injuries may need to avoid lying directly on the painful shoulder. In some cases, sleeping on the opposite side while hugging a pillow can reduce pressure.
Persistent pain, weakness, or numbness should not automatically be blamed on sleeping position. These symptoms may have other causes that deserve assessment.
8. A Pillow Between the Knees Can Improve Comfort
One simple adjustment can make side sleeping more comfortable: placing a pillow between the knees.
When the upper leg falls forward across the lower leg, the pelvis may rotate. For some people, this creates tension around the hips and lower back.
A pillow between the knees can help keep the legs in a more neutral position.
It may be particularly useful for people who experience:
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Lower-back discomfort
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Hip pressure
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Pelvic discomfort
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Stiffness after waking
The pillow does not need to be expensive or specially designed. A regular pillow can work if it is comfortable and provides enough support.
Some people prefer a longer body pillow that supports both the upper leg and the arms.
The goal is not to hold the body in a rigid position. It is to reduce unnecessary strain while allowing natural movement during sleep.
9. Your Pillow Height Matters More Than You Might Think
A pillow that is too high or too low can place the neck in an uncomfortable position.
When sleeping on the side, the space between the head and mattress is usually greater than when sleeping on the back. This means side sleepers often need a pillow with enough height to support the head without pushing it upward.
A useful way to check pillow alignment is to observe whether the nose, chin, and breastbone remain reasonably aligned rather than the head tilting sharply toward the mattress or ceiling.
A good pillow should:
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Support the natural curve of the neck.
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Keep the head from dropping too far toward the mattress.
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Avoid pushing the head excessively upward.
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Feel comfortable throughout the night.
The ideal height depends on shoulder width, mattress firmness, body shape, and personal comfort.
There is no single pillow size that works for everyone.
10. Sleeping Position May Affect Facial Comfort, but Anti-Aging Claims Are Often Exaggerated
Some beauty discussions suggest that sleeping on one side causes wrinkles or makes one side of the face age faster.
There is a reasonable physical explanation behind the idea: when the face presses against a pillow for hours, the skin can experience repeated compression and friction.
Over time, repeated mechanical stress may contribute to sleep-related skin creases in some people.
However, facial aging is influenced by many more important factors, including:
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Age and genetics
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Sun exposure
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Smoking
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Skin hydration
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Facial expressions
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Changes in collagen and elastin
There is not enough evidence to conclude that switching to left-side sleeping will prevent wrinkles or significantly slow facial aging.
If facial pressure is a concern, a comfortable pillowcase with a smooth surface and a pillow that does not force the face into the mattress may help reduce friction.
Good sun protection and avoiding smoking have much stronger evidence for protecting skin health.
11. People With Certain Heart Conditions May Prefer Different Positions
Sleeping position can affect how comfortable someone feels when breathing, especially when certain medical conditions are present.
For example, people with heart failure may experience shortness of breath when lying flat. This symptom is sometimes called orthopnea.
They may feel more comfortable sleeping with the upper body elevated or using additional pillows.
Some people with heart conditions also report discomfort when lying on their left side. This can be related to increased awareness of the heartbeat or other individual factors.
However, discomfort on the left side does not automatically mean that the heart is being compressed or damaged.
The heart is protected by the rib cage and surrounded by structures that allow it to function in different body positions.
There is no universal sleeping side recommended for everyone with cardiovascular disease.
Anyone with new or worsening shortness of breath, chest pressure, fainting, or unexplained nighttime breathing difficulty should seek medical attention rather than attempting to solve the problem by changing sleeping position.
12. Changing Your Sleeping Position Takes Time
People often have a preferred sleeping position developed over many years.
If someone has always slept on their back or right side, trying to remain on the left side throughout the night may initially feel unnatural.
That does not mean the body is rejecting a healthier position.