What's the difference between polycystic ovarian syndrome and cushing disease? how do you know which one you have?

They are very different disorders. You may assume they are similar because both have increased steroid hormones. But entirely different types of steroid: predominantly androgens (male sex hormones) in PCOS and corticosteroids (cortisol and similar) in Cushing's disease. The symptoms, signs, and lab tests are completely different. Discuss with your doctor, or search both online. Good luck.

While there might be overlap in symptoms, these are totally different diseases that sometimes take time and many tests to be properly diagnosed. Do not try to self diagnose, trust your medical team.

Visit these two sites for information. You should consult an endocrinologist. https://www.hopkinsmedicine.org/health/conditions-and-diseases/polycystic-ovary-syndrome-pcos#:~:text=Polycystic%20ovary%20syndrome%20(PCOS)%20is,that%20form%20in%20the%20ovaries. http://pituitary.ucla.edu/cushings-disease