Three inches is about 9 cm now, and four inches is about 12 cm. Now people buy this kind of plastic pillow, the so-called memory pillow. Its height is about 9 cm, which is just in line with the comfort of human cervical vertebra. Therefore, this kind of pillow is more suitable, because its hardness is moderate, and then its height is moderate and light, which will not cause any serious harm to the body. So this kind of memory pillow still has some advantages, but that kind of space cotton pillow is not recommended because it is too soft.
When choosing a pillow, you should choose a pillow with moderate height and moderate hardness. Our traditional buckwheat pillow can also be used. Because the pillow height of buckwheat can be adjusted according to your own preferences, and then the soft and hard are inverted, this way is acceptable, but most people don't bring such pillows when they go out, because they are too heavy, so a memory pillow comes in handy, because it is lighter and the price is relatively cheap. As long as they don't pursue any big brands, the price is basically acceptable, which is more suitable for human cervical vertebra cultivation, especially for some people.
Choosing the right pillow height can make our blood circulation smoother. Because our neck and cervical vertebra contain an important part of our body's water circulation, it is like a complete circulating water pipe. If a certain part is inhibited, it will lead to poor blood circulation and dizziness and fatigue after sleeping. This is that the physical state of sleep is not well grasped, which has a lot to do with pillows.