The thickness of a pillow, known as its loft, plays a direct role in the quality of sleep and overall physical comfort. Loft is defined as the height of the pillow when it rests uncompressed on a flat surface, usually categorized as low, medium, or high. Selecting the appropriate height is a necessary step in ensuring the head and neck remain properly supported throughout the night. An incorrect pillow height can strain the neck muscles, potentially leading to stiffness, tension headaches, and discomfort upon waking.
The Goal of Neutral Spinal Alignment
The primary reason for choosing a pillow’s loft is to maintain neutral spinal alignment. Neutral alignment refers to preserving the natural inward curve of the neck, known as the cervical lordosis, while a person is lying down. When the pillow is the correct height, the head is positioned so the cervical spine remains in a straight line with the rest of the spine. This prevents the head from being tilted too far upward or allowed to drop too far down toward the mattress.
If a pillow is too high, it forces the neck into excessive flexion, pushing the chin toward the chest. Conversely, a pillow that is too low causes the head to sag backward, forcing the neck into unnatural extension. Maintaining the neutral position reduces stress on the vertebrae, discs, and surrounding muscles, allowing them to relax and recover overnight. For side sleepers, proper alignment means the ear should stack roughly over the center of the shoulder without any tilt.
Height Requirements Based on Sleeping Position
The specific loft required is determined by the sleeper’s preferred position, as each posture creates a different gap between the head and the mattress. Side sleepers generally need the highest loft to fill the large space created by the distance from the ear to the outside shoulder. This higher pillow, often between five and seven inches, prevents the head from tilting down toward the mattress. The pillow must be thick enough to keep the entire spine, from the head to the hips, in a straight, horizontal line.
Back sleepers require a medium loft, typically three to five inches, to support the natural inward curve of the neck without pushing the head forward. The pillow must cradle the neck and head gently, preventing the chin from being forced down toward the chest. Using a pillow that is too thick is a common mistake that causes excessive neck flexion and can lead to morning pain.
Stomach sleeping is generally considered the least advantageous position for spinal alignment because it requires the head to be turned to the side, rotating the cervical spine. For those who must sleep this way, the lowest loft pillow, often three inches or less, is recommended to minimize neck strain. Some stomach sleepers opt for no pillow at all to keep the head nearly flat. Placing a thin pillow beneath the pelvis can also help maintain better alignment of the lower spine.
Factors That Modify Ideal Pillow Loft
While sleeping position guides pillow height, physical and environmental factors modify the ideal loft. Shoulder width is a primary variable, especially relevant for side sleepers. Individuals with broader shoulders require a higher loft pillow to bridge the greater distance between the head and the mattress. Conversely, people with narrower shoulders need a lower loft to maintain proper neck alignment.
Mattress firmness is another major factor, as it dictates how deeply the body sinks into the sleep surface. A softer mattress allows the body to sink further, reducing the gap the pillow needs to fill. Therefore, a soft mattress may require a slightly lower loft pillow. A firm mattress offers less compression, requiring a pillow with a greater loft to adequately support the head and neck.
Testing and Adjusting Your Pillow Height
Determining the ideal pillow height focuses on personal comfort and physical response. A practical way to assess a pillow is to have someone check your head and neck alignment while you are lying in your primary sleeping position. For side sleepers, the goal is for the ear to be level with the shoulder, with the nose, breastbone, and belly button forming a straight line. If the head is tilted up or down, the loft needs adjustment.
Monitoring morning symptoms provides the most reliable long-term test of correct pillow height. Waking up with stiffness, a crick in the neck, or shoulder pain indicates that the pillow’s loft is either too high or too low. Many modern pillows are designed with adjustable fill, such as shredded memory foam or down alternative, allowing the sleeper to easily customize the height. If an adjustable pillow is unavailable, a small, rolled-up hand towel can be placed at the base of the neck for added support to test a slightly higher profile.