Thyroid Thursday Episode 55: Hypothyroid Symptoms and Low TSH
Hi everybody, it’s Dr. Eric Balcavage. We’re back for another edition of Thyroid Thursday. Today I want to talk about having hypothyroid symptoms, but your TSH is low or low normal. Sometimes you go to your doctor and you have hypothyroid symptoms, they do just usually a TSH and T4. Your doctor looks at your TSH and says, “Your TSH is low, you’re more hyperthyroid than hypothyroid, so it can’t be a thyroid problem that’s causing your hypothyroid symptoms, so it must be something else. You’re tired, your fatigued, you’re stressed, you’re depressed, you’re eating too much, you’re not exercising enough.”
We’ve talked about that on many of the videos, but there’s something that you should do when you have hypothyroid symptom and you have a low TSH. One of those things you really need to do, is you really need to check your gut and check for infections. I’m going to talk about bacteria, and bacteria specifically that have a coating called lipopolysaccharide. A lot of gram negative bacteria have this coating or this shell on the outside of the bacteria that’s called lipopolysaccharide. This lipopolysaccharide coating can be one of the reasons why you have hypothyroid symptoms, and it can be also what’s causing your low TSH.
Let me explain. Hypothyroid symptoms are the result of low levels of thyroid hormone inside your cells. That’s what causes you to have hypothyroid symptoms. Now that we have that straight, we take a look at what goes on here. Let’s talk about thyroid physiology, the basics. You have your hypothalamus, which is up in the brain. That releases something called thyroid releasing hormone. The thyroid releasing hormone stimulates the pituitary gland, which is also up in the brain, to release something called TSH. This is what your doctor’s typically measuring.
TSH is thyroid stimulating hormone, that stimulates the thyroid gland to make T4 and T3. Once T4 and T3 is released, it gets into the blood supply and then from the blood it is transported inside the cells, and if you have T3 it can actively bind to the T3 receptors. If you have T4 it needs to be converted to T3 so it can be used. That’s kind of the perfect scenario.
For some people, they have chronic infections, and two primary routes of entry are the oral cavity and the GI tract. Let’s talk about the GI tract. A lot of times there is bacterial overgrowth in the GI tract, and some of those bacteria have this lipopolysaccharide coating. If there is damage to the GI tract, there’s inflammation, there’s anything that can cause an overgrowth of bacteria and leakiness of the GI tract, these lipopolysaccharides can get into the bloodstream. They can also get directly into lymph tissue, and once they’re in the lymph tissue, they can be transported to different tissues, especially into the thyroid gland.
How does lipopolysaccharide create hypothyroid symptoms, and how can these lipopolysaccharide or bacteria create low TSH in conjunction with the hypothyroid symptoms?
When you have lipopolysaccharide that gets into the bloodstream, those lipopolysaccharides can go to the hypothalamus. In the hypothalamus, they can actually increase an enzyme called Deiodinase 2. Deiodinase 2 increases the conversion in the hypothalamus from T4 to T3. Now we get saturation of the receptors in the hypothalamus with plenty of T3.
This tells the hypothalamus that we don’t need anymore thyroid hormone, so TRH secretion goes down. If TRH secretion goes down, then there’s a decrease in TSH secretion. When your doctor then runs your lab work, because the hypothalamus is getting this upregulated conversion by the lipopolysaccharides increasing T3, TRH goes down, TSH goes down, you could have decreased T4 and T3. T4 or T3 could still be normal in blood, because bacteria or lipopolysaccharide can also impact the transport of thyroid hormone into your peripheral cells, and we may not have the same activation response going in the cells. We actually may have other deiodinases being activated, so we get more reverse T3 than we are getting T3. When transport mechanisms are decreased, you may get increased conversion to reverse T3 as a result.
If you have low TSH (like it’s pushing more towards the hyperthyroid state) yet you have hypothyroid symptoms, you need to ask your doctor to look for chronic infections. They could be viral, they could be bacterial. This is more of a bacterial mechanism that we’re talking about, because the bacteria have this lipopolysaccharide coating. If your doctor doesn’t know what to do, you want to be looking at something called a CDSA, which is a stool test that looks for different strains of bacteria. You could do something called a GI Map Test, which again, tests for different types of bacteria, some of the gram negative bacteria. The last thing you could do is an Organic Acid Test, which is going to show the metabolites of bacterial overgrowth.
Hopefully this video helped. Hypothyroid symptoms, low TSH, you’re not crazy, you’re not nuts, you’re not eating too much or not exercising enough. It may be chronic infections. A real clue is, if you eat food and get gas and bloating, reflux pressure, if you have slow bowel motility, if you have diarrhea, you have irritable bowel syndrome, these are all reasons to really look at a CDSA, GI map and an OAT test. These will give a doctor who understands functional medicine the right tools to be able to tell you, this mechanism may be going on, artificially suppressing your TSH levels while your cells aren’t getting thyroid hormone. That’s why you’re tired, fatigued, bloated, constipated, gaining weight, and your brain’s just not working. Hopefully this video helped. If you have any questions, put them below wherever you watch this video, and stay tuned for another Thyroid Thursday in the coming weeks.
