Hypochondria

[Shannon]

For most people, it is based entirely in fear.  But I have also seen both of the other possibilities I mentioned.

I must be a notable exception then. I also think that in addition to negativity there may have been an obsessive-compulsive element to it, although getting rid of the negativity cured it for me, even though I still had some fear and OCD for many years after the hypochondria disappeared.

The negativity usually arises as a result of fear.  The OCD is a result of fear.  Hypochondria, OCD and negativity are all just ways in which fear gets expressed.  Different branches of the same tree.