Polyendocrine metabolic ovarian syndrome (PMOS)

There's a condition that for years was called polycystic ovary syndrome and that today goes by polyendocrine metabolic ovarian syndrome, or PMOS. The name changed because the problem was never just about how the ovary looks. It's viewed on three levels at once: whether ovulation happens or not, how active the androgens are, and how the metabolism is running. All three belong to the same condition; they aren't three separate diseases.

In an adult, other causes are ruled out before the name is applied, and after that a single piece isn't enough. At least two of these three have to line up: hyperandrogenism, meaning androgen activity above what's expected; ovulatory dysfunction, ovulation that isn't running the way it should; and polycystic ovarian morphology, ovaries with that appearance. It works like a door with two locks, where one key alone won't open it. That's where the confusion behind the old name becomes clear: some people have PMOS without polycystic-looking ovaries, and finding follicles, or what get called cysts, isn't by itself enough to say the syndrome is there.