What is PCOS?
What is Polycystic Ovary Syndrome (PCOS)?
PCOS is a set of symptoms that are caused by a hormonal imbalance, and it affects about 10 percent of women of reproductive age. Genetic and environmental factors have been found to contribute to the development of PCOS.
A woman is diagnosed with PCOS if she has two of the following three symptoms:
High androgens - This is identified by Unwanted facial hair/ excess hair growth, High testosterone found during laboratory tests, or High DHA found during laboratory tests.
Irregular or lack of periods/menstrual cycle
Polycystic ovaries (Unruptured follicles) - This is normally identified by an transvaginal ultrasound. During the ultrasound the ovaries will be measured and Due to the large numbers of the unruptured follicles the ovaries are large in size (normal ovary size is 5-8 cc, large PCOS ovaries size up to 23 cc), which is very common for PCOS patients.
To understand how a PCOS cycle differs and how they hormones are different from a normal cycle, it is best to understand a normal female menstrual cycle.
Normal cycle:
The phases of a woman's monthly cycle are the follicular phase, ovulation, and luteal phase. The figure shows the ovarian hormones, pituitary hormones, and body temperature. Day 1 of the cycle is the first day of the menses. A normal cycle is 27-34 days in length.
As can be seen in the figure above during the first half of the follicular phase there is little change in the hormones. The body is shedding the lining of the uterus which is the cause for the bleeding. Then to begin the second half of the follicular phase, the estrogen hormone rises. During this estrogen rise, a follicle is growing on one of the ovaries. The endometrial lining regrows in preparation for a fertilized egg. The brain detects this rise in estrogen and triggers a LH (luteinizing hormone) spike. The spike in LH and FSH (follicle stimulating hormone) causes the follicle to rupture from the ovary, which is called ovulation. When the follicle is released it is now considered an egg, and is ready for fertilization.
On the ovaries, the scar tissue from where the egg was released produces progesterone. Progesterone supports the third phase of the menstrual cycle, the luteal phase. Progesterone is there to support the lining of the uterus for the possibility of a fertilized egg implanting. Progesterone also causes the basal body temperature (BBT) to rise during the luteal phase.
After about 14 days if a fertilized egg has not implanted in the uterus, the body recognizes that its not pregnant the cycle will start again with day 1 of the menses.
In the event that there is a pregnancy, an implanted egg produces HCG (human chorionic gonadotropin - the hormone tested for in a pregnancy test). HCG is the signal to ovaries to produce progesterone to ensure a healthy pregnancy. The ovaries continue to produce progesterone throughout the first trimester to maintain the pregnancy.
Now that a normal female cycle is understood, the differences between it and a PCOS cycle should be easy to understand.
In a PCOS cycle, the estrogen, progesterone, LH, and FSH are level. There also is no change in BBT. Also LH and FSH are higher than on the normal cycle figure. And LH and estrogen are constantly elevated. This elevation of hormones disrupts the entire rest of the cycle.
The ovaries constantly develop follicles because the FSH (follicle stimulating hormone) is always signalling for the development of the follicles. And because there is no LH surge, the follicles never get released from the ovaries. Because there is no LH surge, there is no ovulation. Since there is no ovulation, the luteal phase of the cycle does not happen. Since there is no ovulation, the ovaries do not make the progesterone that is needed for the luteal phase. Therefore, there is no progesterone drop to signal when there is no pregnancy, so then there is no menses.
Understanding the PCOS cycle will help attribute the symptoms to how the hormones are acting.
Polycystic Ovaries - In the presence of elevated LH, the ovaries produce more testosterone than estrogen, resulting in a prolonged follicular phase. Due to many factors (not all of which are known), this excess testosterone and lack of estrogen rise results in a follicle “arresting” (stopping) its growth. Normally, with ovulation, a follicle will get to ~2cm, but in PCOS, these follicles stop growing usually before they are 1cm in size. More and more follicles are recruited because ovulation doesn’t happen. This is what results in the “mu
High Androgens - Because the LH is high the body receives that signal to make more testosterone.
Lack of Periods or Irregular periods- The lack of periods can be explained because of the lack of ovulation and no progesterone rise and fall. Since there is no luteal phase, often there is no regular bleeding. Sometimes, a there can be a random ovulation, other times there can be an “estrogen withdrawal bleed”, which results in a “period”, but not a true menses since ovulation doesn’t always occur.
Understanding what is happening in your body is the first step.
Read more to understand how to address it.