Polycystic ovaries are ovaries that contain a higher than normal number of small, fluid-filled sacs called follicles. On an ultrasound, these follicles appear as tiny dark circles clustered around the edge of the ovary, giving it a characteristic “string of pearls” appearance. Having polycystic ovaries is surprisingly common and doesn’t automatically mean you have polycystic ovary syndrome (PCOS), which is a broader hormonal condition with additional symptoms.
What Polycystic Ovaries Look Like
In a typical menstrual cycle, your ovaries develop several small follicles each month, and one of them matures enough to release an egg. In polycystic ovaries, more follicles than usual begin developing but many of them stall partway through. They don’t grow large enough to release an egg, and they don’t disappear. Instead, they accumulate as small cysts measuring 2 to 9 millimeters across.
The current international guidelines, updated in 2023, define polycystic ovarian morphology as having 20 or more follicles in at least one ovary, or an ovarian volume of 10 milliliters or greater. That follicle threshold has actually increased over time. When diagnostic criteria were first established at a 2003 consensus conference, the cutoff was 12 follicles per ovary. But as ultrasound technology improved and could detect smaller follicles more precisely, researchers found the old number was too low and was flagging ovaries that were actually normal. Some studies using the latest imaging have suggested thresholds as high as 28 follicles per ovary to truly distinguish a polycystic ovary from a typical one.
Polycystic Ovaries vs. PCOS
This is a distinction that trips up a lot of people: polycystic ovaries are an ultrasound finding, while PCOS is a metabolic and hormonal condition. You can have polycystic-looking ovaries on a scan and be perfectly healthy with regular periods. Roughly one-third of menstruating women worldwide have ovaries that meet the criteria for polycystic morphology, but far fewer, around 8 to 13%, have the full syndrome.
PCOS requires at least two of three features to be present: polycystic ovaries on ultrasound, irregular or absent periods, and signs of excess androgens (male-type hormones) such as acne, thinning hair on the scalp, or excess facial and body hair. The syndrome is a disorder of the endocrine system with broader health implications. It increases the risk of heart disease, type 2 diabetes, sleep apnea, and, because the uterine lining can build up without regular shedding, it raises the risk of endometrial cancer over time.
If your doctor mentions polycystic ovaries after an ultrasound but you have regular cycles and no other symptoms, you likely don’t have PCOS. The ovarian appearance alone is just one piece of the puzzle.
Why Follicles Get Stuck
The core problem in polycystic ovaries is follicular arrest. Normally, a surge of hormones from the pituitary gland signals one dominant follicle to finish maturing and release its egg. In polycystic ovaries, this process gets disrupted, most often by higher than normal levels of androgens inside the ovary itself.
Androgens interfere with the genes that follicle cells need to expand and mature. Research has shown that when ovarian follicles are exposed to excess androgens, they produce fewer of the growth signals required for an egg to fully develop. The follicle essentially pauses mid-development. When researchers blocked androgen receptors in lab studies, follicle growth and ovulation resumed, confirming that androgen signaling is a key driver of the stall.
Insulin resistance often compounds the problem. When your body’s cells respond poorly to insulin, the pancreas produces more of it. High insulin levels stimulate the ovaries to produce even more androgens, creating a feedback loop. This is why weight management and insulin sensitivity play such a central role in treatment for many women with PCOS.
How Polycystic Ovaries Affect Fertility
PCOS is the most common cause of anovulation (failure to release an egg) worldwide and one of the leading causes of infertility. If you’re not ovulating regularly, the window for conception narrows significantly. But “leading cause of infertility” doesn’t mean “cause of permanent infertility.” Many women with polycystic ovaries conceive naturally, and most others conceive with treatment.
One useful marker is anti-Mullerian hormone, or AMH. Women with PCOS tend to have significantly higher AMH levels, averaging around 6.1 ng/mL compared to 1.8 ng/mL in women without the condition. AMH reflects the number of small follicles in your ovaries, so a high level makes sense when you have many of them. Interestingly, AMH also declines more rapidly in women with PCOS than in other women. For those pursuing IVF, moderately elevated AMH (at or below 5 ng/mL) is actually associated with better pregnancy rates, while very high levels above 5 may reduce IVF success. A high AMH reading shouldn’t be interpreted as a sign of abundant fertility without additional context.
Symptoms You Might Notice
Polycystic ovaries without PCOS often produce no symptoms at all. Many women discover them incidentally during a pelvic ultrasound for an unrelated reason. When polycystic ovaries are part of the full syndrome, though, symptoms can include:
- Irregular periods: cycles longer than 35 days, fewer than eight periods a year, or skipping periods entirely for months
- Excess hair growth: coarser hair on the face, chest, back, or abdomen, driven by elevated androgens
- Acne and oily skin: particularly along the jawline, chin, and upper back
- Thinning hair: gradual hair loss at the crown or temples, following a pattern similar to male-pattern baldness
- Weight gain: especially around the midsection, often resistant to typical diet and exercise efforts
- Difficulty conceiving: due to infrequent or absent ovulation
Symptoms vary widely from person to person. Some women have irregular cycles but no excess hair growth. Others ovulate normally but have significant acne and elevated androgens on bloodwork. The condition doesn’t look the same in everyone.
How Polycystic Ovaries Are Managed
There is no cure for PCOS, but the symptoms are highly manageable. Treatment depends entirely on which symptoms bother you most and whether you’re trying to conceive.
Lifestyle changes are the recommended first step for most women, particularly those carrying extra weight. Even a modest reduction in body weight, around 5 to 10%, can restore more regular ovulation, improve insulin sensitivity, and lower androgen levels. A combination of regular physical activity and a balanced, lower-calorie eating pattern is the standard recommendation. For many women with milder presentations, these changes alone are enough to see meaningful improvement.
When lifestyle changes aren’t sufficient, hormonal treatments can help regulate periods, reduce acne and excess hair growth, and protect the uterine lining from thickening. For women trying to get pregnant, treatments focus on stimulating ovulation. These range from oral medications to injectable therapies, and in some cases, a minor surgical procedure on the ovaries. The specific approach depends on your individual hormone profile and how your body responds to initial treatments.
Because PCOS raises the risk of type 2 diabetes and cardiovascular disease, managing insulin resistance is important even if your primary concern is cosmetic or reproductive. Regular screening for blood sugar levels and cholesterol is a standard part of long-term care.