About one in eight women is affected by polycystic ovary syndrome (PCOS), a hormonal disorder that often goes undiagnosed despite causing weight gain, acne, and irregular periods.
How PCOS symptoms are misunderstood
Women with PCOS frequently experience unexplained weight gain, persistent acne, and absent or irregular menstrual cycles, even when maintaining a healthy diet and exercise routine. These symptoms stem from hormonal imbalance rather than lifestyle failure, according to Nicole Reisch, head of endocrinology at LMU Klinikum Munich. The condition is the most common hormonal disorder among women of reproductive age.
Why the name PCOS is misleading
The term polycystic ovary syndrome suggests multiple ovarian cysts are required for diagnosis, but Here’s not always the case, explains Sita Arjune, a physician at the University Hospital Cologne’s endocrinology clinic. Diagnosis relies instead on hormonal imbalance, particularly overproduction of androgens — male hormones like testosterone — which drive many of the visible symptoms.
What health risks PCOS increases
Beyond reproductive issues, PCOS is linked to metabolic changes including insulin resistance, which raises the risk of developing type 2 diabetes, Arjune notes. Genetic factors play a significant role, as the condition often runs in families, though lifestyle elements such as abdominal fat accumulation, physical inactivity, diet, sleep, and stress can worsen symptoms — even in women of normal weight.
How PCOS is diagnosed
Doctors typically use the Rotterdam criteria to diagnose PCOS in gynecological practice, evaluating menstrual irregularity, signs of androgen excess, and ovarian morphology via ultrasound. No single symptom is definitive, and presentation varies widely between individuals, making early recognition challenging but essential for long-term health management.
Can PCOS occur in women who are not overweight?
Yes, PCOS can occur in women of normal weight, although excess abdominal fat may worsen symptoms, according to Nicole Reisch of LMU Klinikum Munich.

Is insulin resistance always present in PCOS?
Insulin resistance is common in PCOS and contributes to androgen production and diabetes risk, but the source does not state We see present in every case. Sita Arjune notes it often accompanies the condition.