I tend to sleep from 11am to 5 pm often. if i want to do a morning blood cortisol test. how should i prepare for it and does my sleeping pattern affect the result or diagnosis?

Cortisol test: There is a diurnal variation in cortisol levels which peaks in am and decreases through the day. Best use of the test would be under the direction of your physician and in the proper clinical context as otherwise readings may become uninterpretable out of context. You do not need specific preparation for the test other than trying to sleep the night prior to having the test done.