One of the main reasons we use pillows has to do with the complicated relationship between our heads, necks, and spines. When a person is walking upright during the day, the head and neck are held in vertical alignment over the spine by a complex arrangement of muscles and tendons. During sleep, however, many of these muscles relax, causing the head to fall backward or forwards. This places additional stress on the neck muscles and vertebrae, which in turn triggers stiffness in the back muscles and spine.
The solution to this painful situation is to elevate the head and neck until they are back in alignment with the spine, regardless of sleep position. The easiest way to achieve this supported alignment is to use a pillow to achieve the proper angle. When the head, neck, and spine are back in alignment, a person should be able to breathe easier and have improved circulation.
There are several different forms of supportive pillows, all designed to address different alignment issues. An orthopedic pillow is used by most sleepers at night to keep the head, spine, and knees supported in a comfortable sleep position. Some people use pillows between their knees or thighs to provide support for the lower back and hips. A lumbar pillow can also fill the gap between the lower back and a chair or mattress.
A special neck or cervical pillow can also provide additional support while resting in a vertical position. The cervical pillow wraps around the person's neck to push the head slightly forward. Some users find that an improperly sized cervical pillow can cause the user's head to fall too far forward, affecting breathing and creating more strain on the back of the neck or upper back.
Historically, the first cloth pillows were enjoyed almost exclusively by royal families and other wealthy citizens. Lower-class citizens and peasants may have fashioned rudimentary pillows from straw, but more likely than not they used their own arms to provide support while they slept. Widespread use of pillows was not possible until the Industrial Revolution made the wholesale production of cloth an affordable reality.
Certain ancient cultures did not use pillows made from soft cloth and stuffing, however. Pillows were often carved from hard blocks of stone or wood, which did keep the sleeper's head and spine in alignment but could not claim comfort as one of its advantages. Thankfully, modern pillows are available overstuffed with down feathers, foam rubber, therapeutic memory foam, or buckwheat hulls. The trick is to find the appropriate number of pillows to achieve an ideal alignment for a comfortable night's sleep.