1.- Tell everything with detail and do not forget to mention anything that might possibly be related to your problem.
2.- Do not tell lies, for the solution to the lied problem and to the actual problem might be different and could cause you problems.
3.- Make things clear when talking to the healthcare professional.
I don't know if you were looking for any official rules but this ones do help.
Wish you luck!
You can decrease your fat by doing exercise