In the past lectures we talked about why people have low thyroid, what kind of symptoms people with low thyroid often have and what tests doctors do to diagnose the problem.
Actually, I should not say tests, pleural. Usually doctors order just one test, it is called TSH, thyroid stimulating hormone. The job of TSH is to stimulate the thyroid gland into making more thyroid hormones. So if thyroid hormones go down, TSH goes up. And if thyroid hormones become high, TSH will go down. They usually move in the opposite directions.
TSH level is considered “the gold standard” of hypothyroid diagnosis. In most labs, TSH is considered normal if it’s between 0.4 and 4.0. In other words, if your TSH is higher than 0.4 but lower than 4.0, you are considered normal. Even if you have all the symptoms of low thyroid.
We talked about various thyroid hormones, how they are present in the blood either completely free, ready to go to work immediately, or attached to proteins. They are called “bound”, but ready to become free and unbound as soon as the body needs them.
In general, if you think of it, checking just one stimulating hormone to diagnose the disease is silly. We don’t do that with other hormones. The same pituitary gland that makes TSH, also makes stimulating hormones for estrogen, progesterone, testosterone, and cortisone. But if we want to know how progesterone or testosterone are doing, we do not measure Luteinizing Hormone or LH, which stimulates the production of progesterone and testosterone. No, we measure the hormones themselves, progesterone and testosterone. Pituitary also makes ACTH that stimulates the adrenal glands into making cortisol. But if we want to know the level of cortisol we don’t measure ACTH, we measure cortisol. And the same with other hormones.
In case of thyroid, we can do the same thing. We certainly can measure TSH, but we can also measure the levels of thyroid hormones and a few other things besides, which I will mention in a moment.
I have seen many patients whose thyroid was low, but their TSH was not high. So, if I only checked TSH alone and if I were to follow the conventional thinking, I would be misled into thinking that these patients were normal. But I never check only TSH. I check all the thyroid hormones – total T3 (that’s bound plus free), total T4, I check free T3 and free T4, I check reverse T3, and in case of Hashimoto’s I also check antibodies against thyroglobulin and against thyroid peroxidase. They are called TPO antibodies for short.
I have seen many patients whose thyroid hormones, either total or free, were low, yet their TSH level was “within normal limits”, below 4. So they have low thyroid with “normal” TSH. Or how about a patient whole T4 seems OK, but T3 is low. This means she does not turn her T4 into T3 very effectively, which makes her hypothyroid, but her TSH will be fine, because she has enough T4.
Or what about a patient who has seemingly enough T4, but high level of reverse t3, which means that her T4 is mostly turned into an inactive hormone.
And I have seen quite a few patients with a seemingly impossible combination – low T3 and T4 and low TSH. According to conventional thinking this is not possible. When T3 and T4 are low, TSH must be high, unless the patient has a pituitary tumor destroying the gland, which is rare. Yet, I have seen these patients.
As you see, there are many permutations and possibilities. There are also situations when a patient is clearly hypothyroid, but all her blood tests are “within normal limits.” I will have a lecture about that in the future. You can also download a free report about how a patient with a disease can have “normal” blood tests.
The point is that blood tests are just tools that a doctor can use, but not rely on them entirely. Most doctors, when it comes to low thyroid, live and die by TSH. This is wrong.
Let me give you an example from another part of the body. Men have something called prostate, and some men develop prostate cancer. To detect the cancer, doctors measure something called PSA, prostatic specific antigen. Prostate cancer makes PSA go up. In most labs, normal PSA is 4 or less. If a man has PSA less than 4 then we say that he is OK and most of the time we are right. If PSA is above 4, then doctors become concerned. But the truth is that there is nothing magical about number 4. Doctors have found cancer in men whose PSA was 3 or 2 or 1 and even less than 1. At the same time, a person may have PSA of 30 and not have cancer.
The point is, PSA is not a gold standard for prostate cancer and TSH is not a gold standard for thyroid disease. TSH is just one of the tools we have to help diagnose and monitor low thyroid and it should be used with all the other tools.
If you are working with a doctor who is going to do a blood test for low thyroid (TSH), ask him or her to do all the other tests I mentioned. And if they refuse, find another doctor. Or sign up for one-on-one coaching with me.
I have mentioned common hypothyroid symptoms in the past lectures. Next time, I’ll talk about symptoms that are less known.
If you know someone who might be interested in low thyroid, please refer them to LowThyroidDoctor.com so they can download this ebook. Also, if you have questions or comments, please email to DrTeplisky@gmail.com.
As an additional bonus, while available, you can get a free, no obligation 30 min phone consultation with me to see if I can help you figure out if you have low thyroid and what I can do to help you. Just book it online or call my office at 718-769-0997.