Another important consideration is snoring.
Sleeping on the back can make snoring worse for some people because gravity may allow the tongue and soft tissues in the upper airway to move backward, narrowing the airway during sleep. In people with obstructive sleep apnea, back sleeping may increase the frequency or severity of breathing interruptions.
This does not mean everyone who sleeps on their back has a breathing problem. Many people sleep comfortably in this position. But if someone regularly wakes up gasping, experiences loud snoring, or feels unusually sleepy during the day, these symptoms deserve medical attention.
A supportive pillow can help keep the neck in a comfortable position. The arms should also be allowed to rest naturally rather than being forced overhead.
Position 2: Lying Straight With the Arms Beside the Body
The second illustration shows a person lying flat on their back with the arms resting alongside the body and the legs relatively straight.
This is one of the simplest sleeping positions.
People who prefer it may enjoy the feeling of having their body fully supported by the mattress. It can be comfortable for individuals who do not like curling their legs or placing pressure on one side of the body.
The main advantage is that the body can remain relatively symmetrical. When the head, shoulders, pelvis, and legs are properly supported, this position may help reduce unnecessary twisting.
However, sleeping flat on the back is not ideal for everyone.
People who snore heavily or have obstructive sleep apnea may experience more airway obstruction in this position. Individuals with certain forms of acid reflux may also find that lying completely flat makes symptoms worse, especially after eating close to bedtime.
Lower-back discomfort is another possible issue.
Some people naturally have an increased curve in the lower spine. Depending on mattress firmness and body shape, lying flat with the legs extended may create tension in the lower back.
A small pillow beneath the knees can sometimes help reduce this tension by slightly changing the position of the pelvis and lower spine.
The pillow should not be so high that it causes discomfort elsewhere. The goal is simply to find a position that feels natural and supported.
Position 3: The Starfish Position
The third illustration shows someone sleeping on their back with the arms and legs spread outward.
This is commonly called the starfish position.
It gives the body a wide resting posture and may feel comfortable for people who dislike having their arms or legs pressed closely against their sides.
Some people naturally spread out because they feel warmer under blankets or prefer having more space around their bodies. Others move into this position after initially falling asleep in a different posture.
There is no scientific basis for claiming that people who sleep like starfish are necessarily confident, outgoing, or careless.
However, the position can have practical consequences.
Spreading the arms outward may increase pressure on the shoulder joints, especially when the arms are held above shoulder level. If someone has shoulder pain, inflammation, or a history of rotator cuff problems, the position may become uncomfortable.
The legs may also fall outward in a way that changes the alignment of the hips and lower back.
For people who experience discomfort, adjusting the position slightly may help. The arms can rest lower, and a pillow can be placed beneath the knees if that feels more supportive.
Another issue is space.
People who sleep in a starfish position may occupy more of the mattress, which can affect a partner's comfort. While this is not a medical concern, it can influence sleep quality for both people.
The important point is that a wide sleeping posture is not inherently unhealthy. It simply needs to be comfortable for the person using it.
Position 4: The Fetal Position
The fourth position shows a person curled up on their side, with the knees drawn toward the chest and the arms close to the body.
This is known as the fetal position.
It is one of the most familiar sleeping postures. Many people naturally adopt it because it feels secure and comfortable, particularly during colder nights.
Side sleeping can offer practical benefits.
For some people, it may reduce snoring compared with sleeping flat on the back. It can also be helpful for individuals with certain types of obstructive sleep apnea, although side sleeping does not replace medical evaluation or treatment.
Pregnant individuals are often advised to sleep on their side, particularly as pregnancy progresses. The most appropriate position can depend on the stage of pregnancy and individual medical circumstances, so pregnant people should follow guidance from their healthcare professionals.