Almost everyone recognises that human beings are not just physical bodies, but many traditions and therapies have a complex theory of subtle bodies to explain this additional ‘something’. There is some disagreement about how many subtle bodies there are and what they are called. 
Most writers on this subject accept that, as well as there being a physical body, there is also an etheric body, an astral or emotional body, one or more mental bodies and a spiritual body. Many systems include additional bodies. Because of the inter-relation between the bodies, when one of them is disturbed, it affects the other bodies and can lead to physical problems and psychological distress.