How Essential Oil work?

Dr Alan Huch, a neurologist, psychiatrist and also the director of Smell and Taste Research Centre in Chicago says, “Smell acts directly on the brain, like a drug.” Our nose has the capacity to distinguish 1,00,000 different smells, (many of which) affect us without our knowing about the same.
The aroma enters our nose and comes in contact with the cilia, the fine hair inside the nose lining. The receptors in the cilia are linked to the olfactory bulb which is at the end of the smell tract. The end of the tract is in turn connected to the brain itself Smells are converted by cilia into electrical impulses that are transmitted to the brain through olfactory system. All the impulses reach the limbic system. Limbic system is that part of the brain which is associated with our moods, emotions, memory and learning. All the smell that reaches the limbic system has a direct chemical effect on our moods.
For example smelling lavender increases alpha waves in the brain and it is this wave that helps us to relax. A whiff of jasmine increases beta waves in the brain and this wave is associated with an increased agile and alert state.
Limbic system is also a storehouse of millions of remembered smells. That is why the mere fragrance of haystack takes us back to childhood.
The molecular size of the essential oils is very tiny and they can easily penetrate through the skin and get into the blood stream. It takes anything between a few seconds to two hours for the essential oils to enter the skin and within four hours the toxins get out of the body through urine, perspiration and excreta.
Aroma oils work like magic for stress-related problems, psychosomatic disorders, skin infections, hair loss, inflammations, pains arising from muscular or skeletal disorders to name some. Actually essential oils have innumerable applications.
In Bristol, lavender oil was used on 28 patients who had undergone bypass surgery. 24 of them reported reduced breathing rates, lower blood pressure and anxiety levels.
In Paris, in 1985,28 women were given treatment for thrush using essential oils. After 90 days the clinical examination showed that 21 of them had been cured completely.
Essential oils are safe to use. The only caution being they should never be used directly because some oils may irritate sensitive skin or cause photosensitivity. They should be blended, in adequate proportion with the carrier oils. A patch test is necessary to rule out any reactions.