What is the Aura? ...it is a luminous energy body, that surrounds and interpenetrates every person, alternatively called the bio-plasmic body. Think of it as your own personal energy field that protects you from harmful outside influences.
Just like the visible physical body, it has a head, two eyes, two arms and so forth. In other words, the bio-plasmic body is a mirror image of the visible physical body and is also known as the etheric double, or etheric body.
Plasma is ionized gas or, put differently, gas with positive and negative charged particles, its not the same as blood plasma.
The words "bio-plasmic" comes from the word "bio" meaning life and "plasma" which is the fourth state of matter; the first three states being solid, liquid and gas.
This luminous energy body known as the bio-plasmic body means it's a living energy body made up of invisible subtle matter or etheric matter. It is through the energy body that prana, chi or life-force energy, is absorbed and then distributed throughout the whole physical body.
Looking at it another way, all living things (people, plants, animals, etc.) are made up of a complex combination of atoms, molecules and energy cells. As these ingredients coexist, they generate a large magnetic energy field that can be sensed, felt and even seen.
These close-knit electro-magnetic energies of varying densities, that permeate through and emit or exit from the physical body of a living person, are also known as auric layers. Some of these layers follow the body's contours while others form the shape of an oval, which is commonly known as the auric egg. This "auric egg" emits out from the body approximately 60 centimeters (2 feet) to 90 centimeters (3 feet) on all sides. It extends above the head and below the feet into the ground.
These energies make you what and who you are and in turn, are affected by your surroundings and life style. The aura reflects your health, character, mental activity and emotional state. It also shows dis-ease - often long before the onset of symptoms.
Most people consider the material world and the physical body to be the only reality that exists, as only these things can be discerned with the physical senses and grasped by the rational mind.

This system of energy consists of three basic components:
Dis-eases are caused by the depletion or congestion or blockage of chi, prana or life force energy in this energy system. These abnormalities can be seen in the aura and in a lot of instances they are distinguished by certain colors seen in the different layers of the energy body.
Aura Balancing is a good idea to do from time to time to clear out any negative thought patterns and emotional blocks as well as to set a shield of protection around yourself thereby assisting your body to retain much needed life force energy.
Go to - Subtle Energy Bodies of the Aura
Go to - Interpreting the Aura