Missing period?
Why this happens and why we should care: understanding amenorrhea
Written by: Dr. Fiona Callender, ND
Once we get a period, losing it for over 6 months is usually diagnosed as secondary amenorrhea. If we never got a period by the time we turned 15 years old, we call this primary amenorrhea.
Although the American College of Gynaecologists and Obstetricians requires six months to diagnose amenorrhea, other sources only require three months. Three months is more than enough to spark an investigation in my office!
There are a number of potential causes for amenorrhea, that typically fit within three general categories: hormonal changes that lead to a lack of menstrual cycle, damage to the endometrium (the lining of your uterus), or obstruction of the outflow of menstrual blood. There are also physiological (normal and healthy) reasons for losing a period - like pregnancy, lactation and menopause. Hormonal birth control can also often cause amenorrhea - this is common and expected!
For the purposes of this blog post, we are going to focus on hormonal causes including conditions relating to thyroid dysfunction, high prolactin levels, high testosterone, hypothalamic-pituitary dysfunction.
To get to the root of your missing period, you deserve and require an assessment. A big part of this assessment is talking about your symptoms and the history of your amenorrhea. We may ask what your cycles were like before, what your other symptoms are (do you have any acne or hair growth on your face, have you noticed changes in skin or digestion etc), if you’ve had changes in energy level, do you compete in any sports, how do you feel about your body, what are you eating, etc! We also run blood work and, in some cases, imaging.
Let’s discuss some of the of the most common hormonal causes
PCOS
Polycystic ovarian syndrome (PCOS) is the most common endocrine (hormonal) disorder in those assigned female at birth (AFAB). To diagnose, we need two of the following three criteria present: chronic anovulation (long cycles or missed periods), high androgens (either symptoms or on lab work) and polycystic ovaries (found on ultrasound). PCOS can present differently in different people but the main cause of symptoms in most cases involves dysregulation of testosterone production at the level of the ovary and some degree of insulin resistance. These two factors also magnify each other, creating a bit of a cycle. Ultimately, many people with PCOS have many follicles being recruited but that don’t mature or ovulate. When we don’t ovulate, we don’t have a corpus luteum develop and therefore don’t produce progesterone. Unopposed estrogen then continues to stimulate the endometrium to grow (you can see our blog post on menstrual cycle basics to understand this further!).
If this goes on for too long, we can end up with endometrial hyperplasia - the overgrowth of the endometrium. The most concerning aspect of this is the resultant increased risk of endometrial cancer. This is why it’s really important for those with PCOS to seek support if they have gone more than three months without a period.
Hypothalamic amenorrhea
Another common cause of amenorrhea is hypothalamic amenorrhea. This is caused by aberrant hormone signalling from the brain, largely due to reduced energy availability or high stress. Hypothalamic amenorrhea is responsible for 20-35% of secondary amenorrhea - possibly higher in teens. Stress, low energy availability, and excessive exercise are among the main causes. Low energy availability can come from undereating, overexercising, or both! These all signal to the brain that we are not safe or that we need to use our energy for more critical and life-sustaining body functions - not reproduction.
In these situations, hormone release from the brain slows way down, which slows the development of follicles in the ovary. This leads to low hormones all around. On lab work, FSH and estrogen are low. Low estrogen becomes a serious concern over time as it impacts many body systems. Estrogen stimulates bone building and helps with calcium absorption. Chronic estrogen deprivation can have significant impacts on bone health - even in young women! This is especially concerning, knowing that hypothalamic amenorrhea often occurs during peak bone building years! Other important areas of our health that hypothalamic amenorrhea can affect include thyroid health, cortisol (our stress hormone!), fertility, and cardiovascular health.
This is another consideration when someone misses their period. It can also overlap with the two conditions above! PCOS and hypothyroidism often overlap and their symptoms can present very similarly. Hypothyroidism can result in higher prolactin levels, which results in amenorrhea. When prolactin is high, it sends feedback signals to the brain to slow hormone production. In some cases this is normal - like pregnancy. In pregnancy, prolactin levels rise dramatically and then stay high during lactation and breastfeeding. Part of a work-up for your amenorrhea will likely include thyroid and prolactin testing.
Getting to the root cause of your missing period is important for how we will approach treatment. In any of these hormonal conditions (that aren’t physiological states, like pregnancy) there are longer term consequences for not getting your period that we want to address and prevent. You deserve to have this taken seriously.
Want to learn more about how your period can be supported? Book a complimentary meet and greet appointment to learn more about how Dr. Fiona can support your period and fertility goals.