It is your specific body type by Ayurvedic standards. Do a search for "dosha test". This is also a good website to find alot of info about dosh and sub dosha. http://www.ayurveda-ayurvedic.com/doshas/asgb-40.html
All it is saying is, illness comes when you are imbalanced. Your body is made of elements that are present in our earth : water, wind, fire,etc... One is always dominant, but you don't want to feed the dominant one, you want to nurture the weaker ones to create better balance. Balance is the key. When you find out which one is dominant in you, you know what diseases you will be prone to, what times of day to eat, study, and sleep etc...
Good Luck,
Gracey