Pathophysiology & Clinical Presentation

Normal Physiology

Ovaries are organs found on both sides of the uterus in females. Ovaries sit on the ovarian fossa and are connected by ligaments. These important organs have two main jobs: to release female sex hormones, estrogen and progesterone, and to produce ova or eggs.

In a healthy individual, there is a normal hormonal feedback system which enables the body to stimulate the menstrual cycle. A female is born with all the eggs she will produce in her life. Over time these eggs, which are encapsulated in what is termed a follicle, will mature. This happens in the first half of the menstrual cycle. The ovaries will also produce estrogen during the maturation process. In each cycle, one of the mature eggs is eventually released into the fallopian tube, which is called ovulation. The corpus luteum is the leftover follicle, which then releases lower estrogen and increases the release of progesterone into the body. This will prepare the uterus for when the egg and sperm are ready for attachment in the uterus lining. If the egg is not fertilized, menses will begin to shed the uterine lining and another cycle will follow.

Alterations That Occur with PCOS

Polycystic Ovarian Syndrome is a multifactorial endocrine abnormality that leads to ovarian dysfunction of follicle development (Thornton et al., 2015). The follicles will mature to a certain point and then fail to release the egg into the fallopian tube. This is a reason some females with PCOS have trouble conceiving. The enlarged follicles are then considered ovarian cysts. The accumulation of cysts will eventually cause ovarian enlargement.

The specific pathophysiology of Polycystic Ovarian Syndrome is poorly understood, however, practitioners do know that it is a combination of metabolic and reproductive abnormalities (Thornton et al., 2015). Inappropriate gonadotropin secretion, chronic hyperandrogenism, and an increase in estrogen concentration are present in the typical PCOS patient. Although not present in all patients, glucose intolerance and hyperinsulinemia are strongly associated with this syndrome and may aggravate hyperandrogenic states (McCance & Huether, 2019). This occurs as insulin stimulates androgen secretion and reduces a serum globin that binds to sex hormones (SHBG), increasing testosterone levels. Insulin and excess androgens decrease apoptosis and allow the follicles to remain intact in the ovary. Further, it appears weight gain can worsen signs and symptoms of PCOS. Currently, researchers are focusing on the possibility that increased intraovarian receptors for estrogen receptor-α or insulin growth factor 1, elevated leptin levels, or direct infrared radiation within selective ovarian cells may also contribute to the development of PCOS (McCance & Huether, 2019).

Ultimately, dysfunction in the normal hormonal feedback is affected by this prolonged elevation of androgens and estrogen. There is an increase in luteinizing hormone and estradiol and may be a decrease in FSH as well. The diagram below explains how all these alterations interact with one another.

The typical patient presents with several of the following: dyslipidemia, obesity, acne, hair loss, acanthosis nigricans or discoloration in body folds, hirsutism, irregular menses, infertility, dry skin, or changes in the voice (Thornton et al., 2015).

Studies have also shown that practitioners tend to see familial traits associated with PCOS. However, the genetic cause or process remains unknown. It is reasonable to suspect that it is multifactorial and that intrauterine and childhood environments could have an impact (McCance & Huether, 2019). During a thorough reproductive history, it is important to question the patient if PCOS is present in other family members.

Key Criteria for Diagnosis

Practitioners should be aware there are several different diagnostic guidelines. The preferred guideline is Rotterdam Criteria. This can be found in the Diagnosis and Treatment of Polycystic Ovarian Syndrome: An Endocrine Society Clinical Practice Guideline (Thornton et al., 2015).

Rotterdam Criteria requires two of three of the following manifestations:

  • Hyperandrogenism: can be determined based on clinical observation (hirsutism + virilization) or laboratory testing (testosterone, androstenedione, or Dehydroepiandrosterone)
  • Ovulatory Irregularities: important to obtain a thorough reproductive history asking about irregular menses and amenorrhea
  • Polycystic Ovaries: 12(+) follicles in at least one ovary present on transvaginal ultrasound; appear as pearly white capsules when examined

This is an example of an ovary ultrasound in a PCOS patient.


Most diagnoses require ruling out many other disorders before an official diagnosis is made, especially since it cannot be confirmed with the presence of a polycystic ovary alone. It is important to note that PCOS symptoms can mimic normal changes that occur during puberty so an adolescent diagnosis requires all three of these manifestations. A practitioner should also exclude endocrinopathies that mimic PCOS in women of all ages. This can be done by testing TSH, free T4, prolactin, fasting glucose, glucose tolerance test, 17-OHP, and testosterone levels (Thornton et al., 2015).

If there is a rapid onset of these signs and symptoms it would also be important to consider an ovarian or adrenal tumor that is producing androgens. Practitioners should make patients aware that a diagnosis of PCOS can increase a female’s chance of having uterine cancer later on in life (Thornton et al., 2015).

There are many treatments practitioners may use to promote quality of life in PCOS patients. Common therapies include oral contraceptives, lifestyle modifications to decrease weight, a prescription for metformin, and possibly progesterone therapy. The main goal is to reverse the symptoms of hyperandrogenism, restoring fertility, and addressing metabolic concerns (McCance & Huether, 2019).