Thyroid Tests To Ask For

Happy Medical Monday everyone! Let’s talk about thyroid for a bit, since it’s an issue that is coming up for more and more people. Hyperthyroidism is when the thyroid is overactive and producing too much hormone – this is less common but can be quite severe, often resulting in the thyroid being radiated to slow it down. Hypothyroidism, which is way more common, occurs when the thyroid is sluggish and not functioning efficiently. Hashimoto’s thyroiditis is an auto-immune condition which typically involves a shorter phase of hyperthyroidism, followed by a longer term hypothyroidism. To really see what’s going on with the thyroid, lab testing is needed. However, it is typical for doctors to simply run a TSH level and make judgments based on that. This, in my opinion, is insufficient and simply doesn’t give enough information. So today I’m going to give you a list of thyroid tests to ask for when you’re interacting with your doctor.

• Thyroid Stimulating Hormone (TSH) – this is the most commonly-run test, and it’s certainly necessary. TSH is the hormone sent from the pituitary gland to the thyroid gland to give it the signal to produce thyroid hormones. Subsequently when the thyroid is under-functioning, TSH will be elevated, as it’s trying to give louder and louder instructions to the thyroid to produce more hormone. When there is too much thyroid hormone, TSH will be low as it’s telling the thyroid that there’s enough already and it doesn’t need to produce more. TSH ranges are approximately 0.45 – 4.5 in allopathic medical circles. In naturopathic circles we recognize that any TSH value over 2 might be a relfection of sluggish thyroid function, and the following tests should be run.
• Free T4 (fT4) – T4 is one of the two thyroid hormones (T3 is the other one). T4 is produced by the thyroid gland itself, and is circulated throughout the body where it is converted to T3, the active form of thyroid hormone. T4 occurs in higher amounts than T3. Measuring the free T4 as opposed to the total T4 means that we can see the amount of hormone that is unbound, or “bio available” – this is the one we really care about, more so than the total T4.
• Free T3 (fT3) – T4 is converted to T3, predominantly in the body. T3 is the active form of thyroid hormone, so sufficient free T3 is pretty important. Some people do not convert T4 to T3 well (this is dependent on certain enzyme systems and minerals such as zinc and selenium), so to just look at T4 could misrepresent the situation as T4 could be normal but T3 low.
• Reverse T3 (rT3) – reverse T3 is another metabolite that can be made from T4. Rather than being an inactive metabolite, as is argued in some medical circles, rT3 can have quite an impact, putting the breaks on the system. In these cases, giving T4 is not so helpful, as that can just drive more rT3 production. These people do better supplementing with T3 itself. Without testing rT3 we just can’t get a sense of that.
• Thyroid antibodies – to check for auto-immune involvement in thyroid issues. Antibodies produced against the thyroid can cause inflammation, tissue damage and interfere with normal hormone production. These tests include:

1. Thyroid Peroxidase Antibody (TPO) – this is one of the antibodies that would signal auto-immunity in the thyroid – Grave’s disease or Hashimoto’s. It is actually measuring the levels of an antibody that attacks the thyroid.
2. Anti-thyroglobulin – another auto-immune test that assesses antibodies to thyroglobulin, thestorage form of thyroid hormones.
3. TSH receptor antibodies – measures antibodies that attack the receptors that bind TSH on the thyroid itself.
   This might seem like quite an extensive list, but really, if there are thyroid issues present, this is the only way to really hone in on what’s going on, and fine tune treatment. For example, if TSH seems ok, T4 is ok, but T3 is low, that might be more of an indicator to treat with T3 only. Auto-immune issues tend to respond well to T3 as well. See my previous post about the different options for thyroid support; also check out my post on Low Dose Naltrexone, which I use a lot in cases of auto-immune thyroid issues (that post discusses it’s role in fertility but I use it for so many other things). And of course, nutrition is important in thyroid health.

Ask your doctor to run this panel for you and make sure you learn about all your options for supplementation, rather than just taking the standard thyroxine, which is just T4, in a synthetic form. If you have auto-immune issues, and/ or low T3 and/ or high rT3, you will probably need T3 as well or instead. These labs can be easily run by Labcorp, Quest, or any other of the large reference laboratories. It’s worth being proactive with your health to get the best information.