Everyone has an aura. The aura is a cocoon of energy that surrounds the body. It has several layers that correspond to the major chakras. The layer closest to the body corresponds to the first chakra, the second layer to the second chakra and so on out to the seventh layer.

See the illustration below:

The aura can be seen with the naked eye with some training. Michael Crichton, the famous author of "The Andromeda Strain", "Jurassic Park", and "Sphere" wrote a book about his spiritual explorations called, "Travels". In this book, he talks about going to a workshop in Arizona where he learns how to see auras and subtle energies out in nature. It is quite a fascinating read.

Anyone can be taught to perceive the aura by sensitizing their hands. Once you learn the method, you can feel "empty" spaces where the energy feels absent, or stuck places where you feel stagnate energy that isn't flowing.

When you have developed your intuition enough, these energy spots will transfer information to you, telling you exactly what the issue is that is stuck in this particular layer of the aura.

Aside from reading stuck energy, simply noticing which layer of the aura stuck energy is on and the chakra it is near can give you a great deal of information. For example, if I am feeling a persons aura and I perceive some stuck energy near their 4th chakra on the 3rd layer of their aura, this instantly tells me that they are having some type of relationship issue (4th chakra) with someone they are close to wherein they are struggling with an issue related to their personal power(3rd layer/chakra issue).

With practice you can do this type of diagnosis for yourself and others.