Is TSH affected by stress? Yes it is. In this article, we will look at the role of stress on TSH (Thyroid Stimulating Hormone), thyroid function, and what happens in with your body with stress. We will look at how stress can cause both high and low TSH and what each scenario means.
If you're interested in stress and TSH, keep reading we're going to get into the details.
Two Ways TSH Is Affected By Stress
There really are two different ways that stress affects TSH. As a point of reference, the information provided is based on my clinical experience treating patients with hypothyroid and subclinical hypothyroidism and some cases of hyperthyroid. It is also based on my medical school training and some additional cursory research to see if there are any research papers documenting how TSH is affected by stress. For the most part, this information is well-established and there is little debate about how stress affects TSH.
TSH also known as thyroid stimulating hormone is affected by stress through the role of cortisol. Cortisol is the main stress hormone that's secreted in the body when we are under higher stress levels. There are two main ways that cortisol has this effect on TSH. One is through the brain in the hypothalamic-pituitary-access. The other is through reverse T3.
Stress and The Hypothalamic-Pituitary-Access
What is the hypothalamic pituitary access? The hypothalamus is one of the central places where a lot of hormones are controlled from. Because it is the central place, it has to take input from other parts of the brain and body too. Stress is one of them and can have a down regulatory aspect on some of the hormones that come out of the hypothalamus. The hypothalamus is a gland in the brain that secretes hormones that then tell the pituitary to secrete hormones. If there is a down regulation at the hypothalamus, there will also be a down regulation at the pituitary. TSH is the hormone that comes from the pituitary and it tells the thyroid to make more thyroid hormone, specifically T4. So if you have a down regulation in the hypothalamus then you will also have a down regulation and decrease in the TSH. T4 which is produced from the thyroid then feeds back to the pituitary which senses if it has enough thyroid hormone. The feedback from the T4 plus the input from the hypothalamus regulate the production of TSH.
When you are under a lot of stress your TSH can go down but stress does not always lower TSH. Let's look at the role of stress on reverse T3.
Stress, TSH, and Reverse T3
Reverse T3 increases in response to periods of stress and what the body perceives as high stress like inflammation. Reverse T3 is basically a storage compartment for T4. It takes some of this thyroid hormone out of circulation so it can not be used. This is a common lab finding in people that report higher stress. So basically when we're looking at how stress affects TSH it can do two things. Stress can reduce thyroid output through its activity on the hypothalamus and down regulation of TSH. The other side is when cortisol is more prevalent in the blood there is increased production of reverse T3. With more reverse T3 there is decreased availability of the T4 hormone. So what is the net effect of all this stress on the TSH?
With high reverse T3 oftentimes we see a corresponding higher TSH. That doesn't always happen but it does make physiological sense too. There is less T4 around because it's being put into this reverse T3. With this then you have less feedback to the pituitary. The pituitary sees less of the T4 so the pituitary produce more TSH. The net effect is a rise in TSH. If you don't check the reverse T3 you may think the person needs more thyroid hormone because high TSH is in a hypothyroid state. When this happens we need to keep in mind that there is a reason the body is converting T4 into reverse T3.
We also have the opposite effect with stress in the brain as there is a hypothalamic down-regulation to the pituitary. So in that sense you see a decrease in the TSH. When the stress is coming into the body, how long it's there, the degree of stress, etc all play a role in what we will see with the TSH. There is not a definitive answer with what always happens with TSH and stress. The two studies that I found actually came to separate different conclusions. You can find those here:
In my clinical experience, using reverse T3 (and cortisol) is very helpful to understand what needs to be done. You can really start to hone in on what the true TSH number and true thyroid function is. This is regardless of what stress is doing to the brain. In addition, you also have to look at the free t3 and free t4. Put it all together and you can get a pretty clear picture of the thyroid activity and what's going on in the body.
For instance, if you have a high TSH and a high reverse T3, we can say the reason that that TSH is high is from the T4 being stored as reverse T3.
That should give you a better understanding of the affect of stress on TSH. If you have questions on the specific of this article, please ask in the comment section. If you want help with how to interpret your thyroid numbers, click on the link below to get started.