Evidence for the efficacy of aromatherapy in treating medical conditions is poor, with a particular lack of studies employing rigorous methodology. A number of systematic reviews have studied the clinical effectiveness of aromatherapy in respect to pain management in labor, the treatment of post-operative nausea and vomiting, managing challenging behaviors in people who have dementia, and symptom relief in cancer. However, some studies have come to the conclusion that while it does improve the patient's mood, there is no conclusive evidence on how it works with pain management. Studies have been inconclusive because of the fact that no straightforward evidence exists. All of these reviews report a lack of evidence on the effectiveness of aromatherapy.
The inhaled aroma from these "essential" oils is widely believed to stimulate brain function. Essential oils can also be absorbed through the skin, where they travel through the bloodstream and can promote whole-body healing. A form of alternative medicine, aromatherapy is gaining momentum. It is used for a variety of applications, including pain relief, mood enhancement and increased cognitive function.