Thyroid issues are becoming more and more common. It seems like everybody either has a thyroid issue, or personally knows somebody with a thyroid issue. Why is something vital or our survival having issues in so many people? The answer to that question can be put simply: lifestyle. The overwhelming majority of people who experience typical thyroid problems including fatigue, weight gain, depression, and always feeling cold, all have one thing in common. There is some sort of lifestyle factor that is contributing to some sort of dysfunction in the biochemical pathway of the thyroid and its hormones. In this article, we are going to discuss the six major patterns of hypothyroidism, as well as forms of hyperthyroidism, and what symptoms you can expect with them.
Thyroid Physiology
We often refer to the thyroid as the body’s thermostat because it functions to maintain a regular body temperature. Although that is true, that is a very simple way to talk about its function. The thyroid functions to regulate the body’s metabolism, and the brain decides when to either increase or decrease its function in relation to the hormones circulating through the body.
There are two components of what we call the hypothalamic, pituitary, thyroid axis that must do their job before the thyroid can do its thing. The hypothalamus is a brain structure that secretes a hormone called thyrotropin releasing hormone (TRH). This hormone makes its way to the pituitary gland, which sits a little bit behind your eyes and above your palate. The pituitary then releases thyroid stimulating hormone (TSH), which you might recall hearing about or seeing on your thyroid labs. This is a significant hormone, as it tells the thyroid to either increase or decrease the production of thyroid hormone. Endocrinologist as well as functional medicine practitioners use TSH as one of the main determinants in what type of thyroid issues you may be having.
Once TSH reaches the thyroid, it tells the thyroid to begin producing thyroxine, or T4. An enzyme called thyroid peroxidase (TPO) produces T4 by combining thyroglobulin, a protein, and 4 iodine molecules. T4 likes to hang out in the blood for a long time and is a storage form of thyroid hormone. T3 is the form that causes all the changes to metabolism. An enzyme called 5’ deiodinase removes an iodine molecule from T4 and converts it to T3. This T3 can then travel through the blood to various cells throughout the body, where it will enter the cell and cause the DNA within the cell to increase or decrease production of mitochondria, the cell’s power station. A protein called thyroid binding globulin is what carries both T3 and T4 through the blood. Albumin, another protein, carries some thyroid hormone, but not nearly as much.
If you are currently having issues with your thyroid, take a look at your lab work. You’ll notice that there is TT4 and fT4 or free T4, as well as TT3 and fT3 or free T3. Your Total T4 and T3 (TT4 and TT3) reflect the thyroid hormone that circulating in your blood and is bound to TBG, which makes it less available for action. The body converts T3 and T4 to their respective free versions so that peripheral cells can use them.
I’ve included a flow chart here to provide a visual version of the in-depth explanation above. As you can see, there are many steps, and errors at any of these steps are what cause differing thyroid issues.
Patterns of Hypothyroidism
There are six major patterns of hypothyroid that are known. These can be divided even further, but clinically, it doesn’t make a difference. These six patterns of low thyroid function all lead to similar symptoms of fatigue, weight gain, dry skin, and overall loss of energy.
1. Primary hypothyroidism – In this case, TSH will be greater than 4.5 on blood work and T3 and T4 will be low to normal. This is a situation where thyroid medication is often the answer if there is some sort of tumor or other non-functional cause to the increased secretion of TSH by the pituitary.
2. Functional hypothyroid – This is the most common thyroid issue seen in a functional medicine practice. In this case, TSH tends to be lower than 1.8 on blood work with your T3 and T4 following suit. The caveat is that T3 and T4 are low in regard to functional standards, but not the medical standard. In this patient, you will see the symptoms of hypothyroid, but labs will never fall low enough to warrant medication. This pattern is caused by stress. Not only what you would normally think of as stress, but excess stress hormones due to blood sugar dysregulation. When there are excessive fluctuations in blood sugar, you’ll experience increases in stress hormone production that can lead to down regulation of the thyroid. This is helpful during times of sickness or injury, but not in normal life.
Hashimoto’s – There is another situation where an autoimmune response to either TPO or thyroglobulin causes hypothyroidism. There are often antibodies present, but in very small amounts where they won’t cause the immune response leading to hypothyroid. In Hashimoto’s, there is a significant amount of antibodies. Lab values vary for antibodies, so it is difficult to say what the threshold is. I recommend referencing your lab work and it’s reference ranges. TSH is elevated and T3 and T4 are low in Hashimoto’s. Chronic infections or toxicities cause an imbalance in immune cells, which leads to production of antibodies that then attack various tissues in the body, which is autoimmunity. Treatment for this type of hypothyroid consists of treating those infections and can be a bit more difficult than other types. Gluten intolerance is a very well-known and researched cause for Hashimoto’s in some cases.
3. Under conversion of T4 to T3 – Chronic inflammation and an increase in stress hormones often causes this pattern of hypothyroid. Which isn’t too far off from the previous example. Oftentimes, we treat this pattern the same way as the functional hypothyroid mentioned in number 2. We identify the stressors and help the body deal with them. Infections, blood sugar dysregulation, and poor lifestyle choices are big contributors to that inflammation and increased stress hormone. The big difference in this example is that TSH tends to be normal as well as T4 and fT4, but T3 and fT3 are low, leading to a decrease in the usable thyroid hormone.
4. Over conversion of T4 to T3 – Increased testosterone in women causes this pattern. Insulin resistance (caused by long-term poor lifestyle and blood sugar dysregulation), which goes hand in had with PCOS, often causes high testosterone. TSH is normal in this pattern, but T4 and T3 are high to normal. Why would this by hypothyroid then? Long term insulin resistance and high testosterone causes increased production of thyroid hormone. When thyroid hormones are high for a long time, the tissues in the body become resistant to it, leading to feelings of fatigue, tiredness, and weight gain, the typical hypothyroid symptoms.
5. TBG elevation – In the presence of excess estrogen, the thyroid produces more thyroid binding globulin (TBG). When thyroid hormone is bound to TBG, it can’t be used by the peripheral cells to increase metabolism. If there is too much TBG, it will bind to all the fT3 and fT4, leaving little for use. Fun fact, excess estrogen is often caused by hormone replacement therapy and hormone disruptors such as types of oral birth control. Estrogen has a higher affinity for TBG than T3 and T4, so do your due diligence in asking questions before taking hormone replacement therapy or birth control. Labs for this pattern will include normal TSH and low fT3 and fT4.
6. Thyroid resistance – In this situation, everything would appear to be working normally on labs. The issue lies in the peripheral cells becoming resistant to the thyroid hormones. This can be due to inflammation, infections, heavy metal toxicities, liver congestion, and gut dysbiosis. This example can also show with high testosterone.
Hopefully at this point, you’re realizing that stress, inflammation, and infections are causes for most patterns of hypothyroidism. Fortunately, those aren’t usually hard things to fix!
The Less Common Hyperthyroidism
Hyperthyroidism isn’t nearly as common as hypothyroidism. The mechanism that causes it is typically due to autoimmune issues from chronic infections or toxicities. It can arise due to various tumors, but those are rare. Hyperthyroid is referred to as thyrotoxicosis, meaning toxic thyroid (toxic with too many hormones). The most common type of thyrotoxicosis is Graves’ Disease. An aberrant immune response causes an increase in production of antibodies that attach to the same receptor as TSH on the thyroid cell in Graves’ Disease. We call this an autoimmune hyperthyroid. The attachment of these antibodies to the TSH receptor triggers an increase in thyroid hormone synthesis just as it would with TSH, only amplified.
Some signs and symptoms of Graves’ include heart abnormal heart beat, chronic infections, always feeling warm or hot, excess sweating, bulging eyes, anxiousness, difficulty sleeping, and high blood pressure. Medical treatment for hyperthyroidism involves anti-thyroid drugs, radioactive iodine, and even removal of the thyroid. The functional medicine approach tends to involve treatment of underlying infection or toxic exposures that could lead to autoimmunity as well as helping the body clear thyroid hormone out of circulation.
How to Encourage Thyroid Health
Although there are a lot of things that can cause increased or decreased thyroid function, there are steps that you can take to improve your health and potentially ease thyroid symptoms from home. In review, the causes of many thyroid issues include inflammation, infections, and stress. What can you do to help?
1. Take steps to decrease stress in your life. Practice meditation, prayer, yoga, or mindfulness to allow your mind to calm down. Life is hectic, take time to wind down.
2. Get your blood sugar right. I’m sure you’ve heard this before, but breakfast really IS the most important meal of the day. Breakfast should be high in protein and fat with some complex carbs. Make sure you’re eating three meals a day with those same high protein and fat levels without snacking. Three meals a day that are high in protein and fat without snacks is an excellent way to regulate blood sugar.
3. Take some fish oil. Fish oil is great for many things, but it also helps your body clear out inflammation.
As far as it goes for infections, autoimmunity, and deeper issues contributing to stress and inflammation, I can’t offer any recommendations without thorough history and examination. If you have any known or suspected thyroid issue or have any questions about this article, I encourage you to book a free consultation with me here. Thank you for reading!