Understanding Polycystic Ovary Syndrome PCOS

Periods are erratic, getting pregnant doesn't go well, and acne stubbornly keeps coming up along the jawline. In the clinic, many people come in after worrying about these three things separately. But when they search and run into the unfamiliar word "polycystic ovary syndrome," they usually pause. The name sounds heavy, but it is a condition whose direction of management becomes clear once you know its substance. Today, I will calmly organize the scattered symptoms under a single keyword, from the mechanism of onset to diagnosis and treatment.

Polycystic ovary syndrome is written in English as PCOS, that is, Polycystic Ovary Syndrome, a common endocrine disease of women of reproductive age. There is one point I want to emphasize here. Because the name contains "ovary," it sounds like a problem only of gynecology, but in essence it is a systemic endocrine disease in which hormones and metabolism are intertwined.

At the core of the onset mechanism there are two axes. One is the relative increase of male hormone action, and the other is insulin resistance. When insulin does its job less, the body secretes more insulin, and this excess insulin stimulates the ovaries' production of male hormones and interferes with ovulation, continuing as a vicious cycle. This is the reason that menstrual irregularity, acne, and hirsutism come together in one place.

Diagnosis does not end with a single ultrasound image. The 2023 international evidence-based guideline (led by Monash University, jointly endorsed by ESHRE·ASRM) organizes, based on the 2003 Rotterdam criteria, that for adults a diagnosis requires satisfying at least two of the following three and excluding other causes.

One important change in the 2023 revision is that AMH has entered as an indicator that can substitute for ultrasound. Also, if both menstrual irregularity and hyperandrogenic findings are clear, the diagnosis is considered simpler even without ultrasound or AMH. Conversely, we do not immediately conclude PCOS just because only a "polycystic ovarian shape" is seen on ultrasound. It is also worth remembering that in adolescence the ovarian morphology criterion is not applied.

To rule out other causes, we also check thyroid function test (TSH), prolactin, 17-OH progesterone, FSH·LH, testosterone, fasting blood glucose and insulin, and so on. For adults, menstrual irregularity is commonly considered as a cycle of less than 21 days or more than 35 days, or fewer than 8 periods per year. However, stress, rapid weight changes, excessive exercise, and sleep problems also affect periods, so rather than judging alone, I recommend referring to Checklist guide for an irregular menstrual cycle and getting an accurate examination.

If you narrow PCOS down to a problem of "periods only," it is easy to miss the truly important part. From clinical experience, this condition is connected to whole-body health over the long term.

• On the metabolic side, the risk of type 2 diabetes, dyslipidemia, hypertension, and cardiovascular disease can rise, so regular checks of blood glucose, lipids, and blood pressure are recommended. In particular, when obesity accompanies it, the diabetes risk is reported to rise further.
• On the endometrial side, if ovulation is irregular for a long time, the endometrium cannot shed on time, which can increase the risk of endometrial hyperplasia and, rarely, cancer. However, since the absolute risk is low, rather than uniform screening, an approach of protecting with progestin when needed is taken.

Emotional health is also an area for which the guideline recommends screening. It is reported that depression and anxiety not uncommonly accompany it, and this is not a matter of willpower but one aspect of the condition. This part is covered more deeply in a separate article, so here I will only note to the extent that "mental health should also be taken care of together" and move on.

It is easy to think of medication first, but the 2023 guideline recommends, regardless of whether one plans pregnancy, healthy eating habits and regular exercise first for all women with PCOS. In the clinic too, we always start from here.

There is a point of misunderstanding to clear up. Even if weight loss is not achieved, healthy lifestyle habits themselves are reported to help improve hormonal and metabolic indicators. Since there is not yet sufficient evidence that a particular diet is clearly superior to another diet, a sustainable, balanced diet becomes the realistic goal. This means that unconditional weight loss is not the first button. Considering Management when weight gain accompanies and Checking from the metabolic syndrome perspective together makes it easier to set direction.

PCOS is not a treatment that ends in one go. The path diverges depending on what symptom is most uncomfortable now and whether one is planning pregnancy.

If there is no pregnancy plan, symptom control is the center. A combined oral contraceptive (COC) is recommended as the first-line drug for regulating the menstrual cycle and improving male-hormone symptoms such as acne·hirsutism. Rather than designating a specific preparation, the guideline prefers ones with a low ethinylestradiol dose and fewer side effects. If treating hirsutism with the contraceptive for 6 months or more still gives an insufficient response, adding an anti-androgen drug, on the premise of certain contraception, can be considered. When insulin resistance or metabolic risk is prominent, metformin is sometimes used together.

When planning pregnancy, the core is ovulation induction. The 2023 guideline recommends letrozole as the first-line ovulation-induction drug in women with ovulatory PCOS who have no other infertility factors. This is because higher ovulation rates and live-birth rates were reported compared to clomiphene. If the response is insufficient, combination with metformin, gonadotropins, ovarian procedures, and the like are reviewed as the next steps. For overall pregnancy preparation, the Pre-pregnancy test guide and Menstrual pain·menstrual irregularity management pages are helpful.

PCOS is a complex syndrome in which ovulation, hormones, and metabolism are intertwined together. So the backbone of treatment lies in adding medication tailored to individual symptoms onto lifestyle improvement, and in looking at metabolic health such as blood glucose and lipids, as well as emotional health, together over the long term. Rather than being frightened by a single diagnostic name, it is far more practical to first sort out what symptom is hardest for me right now.

If you have grown anxious from repeatedly searching alone, I recommend checking gynecological symptoms overall while building a plan that does not overdo it based on examination results. For any questions, please feel free to inquire about PCOS-related symptoms by chat.

Written by: Lee Dong-hee Director · Obstetrics and Gynecology Specialist · View doctor profile

First published January 25, 2026 · Last reviewed May 30, 2026

References: 2023 International Evidence-based Guideline for the Assessment and Management of PCOS (Monash University, ESHRE, ASRM, 2023), Recommendations from the 2023 PCOS Guideline (J Clin Endocrinol Metab, 2023), Korean Society of Obstetrics and Gynecology

This article is intended to provide general health information and does not replace individual diagnosis or treatment. If you have symptoms, please consult through a medical visit.