Aroma Therapy, or the treatment with scents, refers to the use of essential oils extracted from natural ingredients to treat medical symptoms, whether infectious skin diseases, depression, malfunctions of  body systems including hormonal systems. The use of essential oils has been recognized by medical societies around world, and has gained interest from experts of many fields who conduct researches to be used in their respective fields.

The study of differences in personality based on blood types is one of those fields that focus on using scents to heal people according to their blood types by studying the characteristics of smells that have specific effects for people of each blood type. ABO Therapy collects and classifies scents in a systematic fashion in order to create the maximum benefits for people who receive the therapy. There are many ways to apply scents in the therapy based on blood types, for instance aromatherapy massage, or mixing scents in cosmetics. Scents improve the circulation of blood, maintain balance, restore physical and mental health, and strengthen body’s immune system. When the body is exposed to scents whether through nose or skin, small molecules in scents are passed into the limbic system of the brain that controls emotions and feelings and associates them with experience and memory. This limbic part of the brain is also directly connected to the brain that controls breathing, heartbeat, blood pressure, stress levels, and the balance of hormones.

Inhalation is one of the fastest and most effective way to achieve physical and neurological results. When inhaled, scents will enter the bloodstream through the tissues of the lung and through the olfactory system. The scents will affect many parts of the brain, such as Hypothalamus, which serves as the command center to bring the body back to balance; the Pituitary Gland, a ductless gland that produces various hormones; and the cortex, which controls learning. The reaction of the body after exposure to scents suitable for blood types is the efficiently stimulated cells, organs, and nervous.