By
Melbourne Functional Medicine
Vicki van der Meer
Medically reviewed by:
In our clinic I see a lot of people who either have a diagnosed thyroid condition, or over the course of working with us, a thyroid condition is uncovered. Although I treat a lot of men with thyroid disorders (particularly hyperthyroidism), the majority of my thyroid patients are women.
It is estimated that women are 5 to 10 times more likely to develop thyroid disorders than men.
The gender difference can be accounted for in part by the autoimmune nature of many thyroid disorders (such as Hashimotos and Graves disease). It’s assumed autoimmune disease occurs more frequently in women than men due to the effect the sex steroids oestrogen and progesterone have on the immune system.
There are many signs and symptoms of thyroid dysfunction that are common amongst males and females. However, females will experience some symptoms differently to males because of how the thyroid hormones interact with and affect female reproductive hormones and in turn how the reproductive hormones influence thyroid function. The differences lie in the effects of thyroid hormones on female reproductive hormones, and vice versa.
Some of the common symptoms of thyroid dysfunction include:
Symptoms of a thyroid disorder that are particularly relevant to women often stem from the thyroid's effect on the menstrual cycle and fertility.
An uncontrolled thyroid condition can cause stress across the hormonal system, impacting the hormones of the female reproductive system. Both hypothyroidism and hyperthyroidism can cause the following menstrual changes:
It’s important to note that many of these menstrual symptoms could be caused by other things besides a thyroid disorder, such as polycystic ovarian syndrome, uterine fibroids or hypothalamic amenorrhoea.
When a thyroid disorder (whether it’s hypo or hyperthyroidism) impacts ovulation, this will have a direct impact on fertility and the ability to conceive, as there can be no conception without ovulation. An untreated thyroid disorder will impact reproductive hormone balance, affecting the quality of the uterine lining and potentially egg quality, further complicating the chances of conception.
There are several unique changes in maternal thyroid hormone metabolism during pregnancy, including a decline in iodine in the body. In parts of the world where there is an iodine deficiency, this can induce maternal hypothyroidism and goitre. According to the Australian Bureau of Statistics, Australian women are more likely to be iodine deficient, and they have lower median iodine levels than men. In iodine-replete regions of the world, this change is less likely to cause a change in thyroid function. In Australia, there is a risk of iodine deficiency due to a change in eating habits including a reduced intake of high iodine-containing foods such as seafood, seaweed and iodised salt. Australia’s soil is also low in iodine, meaning food grown in certain regions has lower iodine content.
Both hyper and hypothyroidism can occur in the postpartum period as a result of thyroiditis. Postpartum thyroiditis is a transient form of autoimmune thyroid dysfunction that generally occurs within 3 to 6 months postpartum.
I treat a lot of women who are either perimenopausal or menopausal. Based on their symptoms, looking into thyroid function is something I will always consider. As perimenopause is a time of significant hormonal change, there is no surprise that there is an increased risk of a thyroid disorder developing at this time. It’s important to consider that many of the symptoms of perimenopause overlap with those of a thyroid disorder.
Signs and symptoms such as menstrual irregularities, mood disorders, increased sweating, weight gain and sleep disturbances could be due to either the fluctuations in oestrogen and progesterone levels or the development of a thyroid disorder.
Diagnosis of a thyroid disorder requires an extensive thyroid panel to be run. Often in a medical setting only one thyroid marker, TSH (thyroid stimulating hormone) is tested. This only tells us part of the thyroid story, and thyroid dysfunction may not be visible by only looking at this one marker.
If I suspect the thyroid might be playing a part in a patient’s health picture, I‘ll look at an extensive thyroid panel which includes all of the other thyroid markers such as T3, T4, reverse T3, and thyroid antibodies.
When investigating menstrual cycle symptoms as well, this might be done in conjunction with a DUTCH test (Dried Urine Test for Comprehensive Hormones).
If you’ve been experiencing symptoms like changes in your menstrual cycle, unexplained weight fluctuations, or persistent fatigue, it’s worth considering whether your thyroid might be involved. Thyroid disorders are common, especially in women, and the symptoms can often be mistaken for other conditions. Reach out to your healthcare practitioner to discuss your symptoms and consider getting a comprehensive thyroid evaluation.
