It's probably a psychosomatic disorder, now called psycho-physiologic disorder rather than a true conversion disorder.

http://www.depression-guide.com/psyc...c-disorder.htm

Conversion disorders are usually directly related to an incident (lose voice when due to speak) and temporary:

http://www.mayoclinic.com/health/con...877/DSECTION=1

Like Mouse says, his therapy/therapist should address his childhood/growing up problems but perhaps you two could take a stress reduction class together or something to help him learn to relax and work on diet, fitness and you all's lifestyle if that is a problem for either of you.