Your comfort while sleeping can be greatly impacted by the thickness of the mattress, which is its height or depth. Choosing the right mattress thickness provides Comfort and base layers in sleeping. Your health may suffer and your quality of sleep may suffer if you sleep on a mattress that is too thin or thick. But because mattress thickness impact have more layers, they are less durable, soft, and supportive. Certain mattress layers provide sleep comfort and thickness for specific body parts, such as the head, shoulders, back, hips, and feet.