There are a lot of changes that can occur during perimenopause. Your hair can thin, you can gain weight (especially in your waistline), you may have new or worsening headaches, and your periods start becoming irregular.
However, what a lot of women don’t realize is that these exact same symptoms can also be due to hypothyroidism.
Hypothyroidism is when your thyroid gland under-produces thyroid hormones. While the under-functioning of any endocrine gland (meaning a gland that makes hormones) would cause some disruption, hypothyroidism can have a number of symptoms and is quite common, affecting almost 1 in 10 women.
In fact, unlike other endocrine disorders, the list of symptoms associated with hypothyroidism is literally over 6 pages long so it can be difficult to identify without proper testing.
And as I mentioned above, some of the symptoms of hypothyroidism are identical to the symptoms of perimenopause, which can make things even more confusing to discern what is really going on.
While I have not seen any research showing perimenopause causing or exacerbating hypothyroidism, the onset of hypothyroidism is common among women of the perimenopause age. In fact, some clinicians have started calling it “thyropause” because of how common the occurrence is.
Since most hormones, by definition, travel through the blood, they influence each other in a web-like effect, which is why endocrinology can be such a complex area of medicine. So, we can’t look at one endocrine issue like hypothyroidism and not consider other hormones as well. When it comes to perimenopause, we can’t ignore the connection between your thyroid, menopause, and adrenal glands.
After we transition through menopause, your ovaries slow down hormone production, but never shut down completely. Instead of shriveling up and dying (one wonderful term used to described menopause centuries ago was “death of sex”), it’s more like your ovaries are starting to go into retirement.
To make up for the decline in production, your adrenal glands (another endocrine gland) help out. Your adrenals make several hormones but most important to perimenopause are dehydroepiandrosterone (DHEA) and cortisol.
In an upcoming article we’ll discuss DHEA and cortisol in more depth, but your adrenal function also affects thyroid function. So, if your adrenals are not up to their peak performance (which can happen from stress, nutrition, or basically a Westernized lifestyle), it can negatively impact your thyroid function and cause hypothyroidism.
So, let’s sum up those complex web-like endocrine interactions: lower functioning adrenals worsens perimenopause symptoms and can cause poor thyroid function; poor thyroid function can also mimic perimenopause; and poor thyroid function is common as we enter perimenopause just due to our age.
Now when it comes to supporting your thyroid, it really depends on where the imbalance is or that underlying root cause of dysfunction. Thankfully, we can generally get some answers through comprehensive thyroid testing.
In order for your body to produce thyroid hormone, the process starts in your brain. Your hypothalamus produces TRH (thyrotropin-releasing hormone). TRH then stimulates your pituitary (still in your brain) to produce and release thyroid-stimulating hormone (TSH).
TSH leaves your brain via your blood and tells your thyroid gland to release your actual thyroid hormones. You have two main thyroid hormones: triiodothyronine (known as T3) and thyroxine (known as T4). Both of these hormones are produced by your thyroid gland but T4 is made in higher amounts compared to T3. However, T3 is the more active form of your thyroid hormones and will be converted from T4 in the rest of your body, particularly your liver.
Since T3 is essentially more potent than T4, if T3 is low but your T4 is normal, you will be more likely symptomatic.
The most commonly (and usually only) run test to evaluate for thyroid is TSH. The idea behind testing TSH is that if your levels of thyroid hormones (T3 and T4) are too low, it will raise your TSH because you’re trying to stimulate your thyroid gland to make more hormone.
The problem with only testing TSH is that doctors assume that the thyroid and brain are following this pattern. But they are not evaluating what your thyroid gland is actually producing. I have seen time and time again where TSH comes back as “normal” but the thyroid hormones themselves are being underproduced.
Once in a while, your doctor may throw in a total T4 in addition to testing TSH. But this again, is problematic.
As we discussed, T3 is the more potent thyroid hormone compared to T4 so if your T4 is normal, but you still have thyroid symptoms, you may not be converting enough to T3.
It is also important to note, we want to check the free versions of these hormones (so free T3 and free T4, sometimes abbreviated as fT3 or fT4) and not the total. Free hormones are what are available for your body to use as they are not bound to a protein. So, you may have normal total levels of the thyroid hormones but the free forms are low and causing symptoms.
An easier way to think of this is if you had money deposited into a 401K and your general checking account. The money in your checking is available to use immediately (so free T3 or free T4) but if that account becomes low, you can’t just easily take money from your 401K. That money is unavailable. Or in the case of your thyroid, you may have adequate amounts of T3 or T4 but they are not available to be utilized.
Now the other issue I commonly see beyond not thoroughly testing the thyroid hormones (and there’s still more to check for that we’ll discuss) is to only look at the conventional ranges.
When you think about lab testing, the ranges that are used are an average of the population. I’m sure you’d agree that our average population is not healthy. Diabetes and pre-diabetes affect over 100 million people in the United States and heart disease is another 28 million.
So, if you’re told your thyroid results are “normal”, consider what normal actually means. Some women can have subclinical hypothyroidism meaning they have thyroid symptoms, but their labs are normal. This is why I always look for optimal levels for thyroid tests.
Another thyroid hormone test that I’ve started running more frequently is rT3, or reverse T3. This is essentially your storage form of T3 so if this is elevated, your body may be storing more of your T3 than you want it to, again causing symptoms. So similar to total versus free hormones, the T3 is not available to be used.
Lastly, another component to consider is to evaluate for autoimmune thyroid conditions. Hashimoto’s is an autoimmune condition that is the most common form of hypothyroidism.
It’s good to get tested and evaluate for this as most people with hypothyroidism have Hashimoto’s. In fact, I’ve had several patients that have been diagnosed as hypothyroid for years but were never tested for antibodies. When we tested them, they were positive for Hashimoto’s.
When we evaluate for Hashimoto’s, we’re testing someone’s antibodies. Antibodies are essentially markers that will bind to a cell and mark it for destruction. They are a part of your immune system, communicating to other parts of your immune system, “This cell is foreign, and it’s not supposed to be here so get rid of it!”
Obviously, this system works great against bacteria, viruses, etc. But with any type of autoimmune condition, such as Hashimoto’s, your immune system is confused and targeting the wrong cells.
The antibodies I commonly test for to evaluate for Hashimoto’s is called TPO (thyroid peroxidase) antibodies and anti-thyroglobulin antibodies. These can be quite elevated with Hashimoto’s.
To sum it up, a thorough thyroid panel would include testing TSH, free T3 and free T4, reverse T3, and TPO and anti-thyroglobulin antibodies.
So, if you have the sneaking suspicion that your thyroid may be to blame for some of your symptoms and all that’s been tested is TSH and maybe total T4, you should consider asking your doctor for a more thorough panel. This may just be that piece of the puzzle that’s been missing all along and is crucial to evaluate for in perimenopause.