Our sense of smell is directly wired to the brain’s centers of memory and emotion. Cells inside the nose detect smells in our environment, and send information to the brain, via the olfactory nerve. (We also have a cluster of cells the top of the throat that detect scents from the food we consume, and pass that information along the same olfactory channel to the brain.) The information about smell does immediately to the limbic system of the brain, which includes regions like the amygdala that control emotional reactions and memory.
While some of the causes of sleep disorders cannot be controlled or mitigated by essential oils, the soothing and relaxing qualities of these oils can help calm the body and mind, making it easier for people to find restful sleep. This is due to the sedative, anxiolytic, anti-depressant, soothing, warming, anti-inflammatory, and analgesic properties of these essential oils.