Do you know your thyroid numbers?
If you read our other post about thyroid health, you now know a lot about this important organ, including what it is, what it does, symptoms and possible causes of thyroid issues, and how diet can play a role in managing thyroid health.
We now want to talk more about the medical aspect to thyroid health – your lab values. Labs are the best way to know the details of what’s going on with your thyroid, but you have to have the right information. So we’re diving into what exactly a full thyroid panel is, and why you may need one.
Why you may need a full thyroid panel
If you request your thyroid to be tested from your doctor, you’re likely to get just one or two labs ordered. This is because most doctors are taught that labs like TSH and T4 (which we’ll explain more in a minute) are all that is needed to start with, and may only agree to order additional labs if abnormalities are found in those. In addition, some insurance companies will only pay for basic thyroid labs, yet this doesn’t give you the full picture.
When it comes to looking at health from an integrative and holistic perspective, a complete picture is always needed to determine what’s going on in the body. Even if one lab is “normal”, it may not be when compared to other labs. You may benefit from a full thyroid panel if you have symptoms of thyroid issues (outlined on our blog here) but may have been told your thyroid function was “normal”, and especially if you are on any thyroid medication. It’s also a good idea to ask for a full thyroid panel from the beginning, before any diagnosis is made or medication is used, since it will provide the most accurate information about your thyroid health.
In addition, thyroid disorders, including hypo and hyperthyroidism, come in two versions: primary and secondary. Primary versions occur when there are problems with the thyroid gland itself, while secondary versions are caused by disorders of the pituitary gland or hypothalamus. Checking individual labs alone does not tell which type of thyroid issue may be present, which is another reason why a full thyroid panel is often warranted.
What’s included in a full thyroid panel
Here are the variety of labs that would be included in a full thyroid panel:
- TSH: This stands for thyroid stimulating hormone and is the most standard thyroid lab to be drawn. TSH is released from the pituitary gland in the brain to communicate with the thyroid.
- Free T4: T4 and T3 hormones are made in response to TSH, with T4 being the main thyroid hormone circulating in the blood. These hormones can be free or bound to different proteins in the blood, and free T4 is the unbound form. It is considered to be more accurate than testing T4 alone. T4 must be converted into T3, so the two labs should always be checked together.
- Free T3: T3 tests are often used to diagnose or test the severity of hyperthyroidism, in which case T3 levels would be elevated. Free T3 is the more active, usable form of your thyroid hormone.
- Reverse T3: This is a biologically inactive and unusable form of the T3 hormone.
- Thyroid antibodies: These labs show the immune systems response to the thyroid and can indicate whether an autoimmune condition is present (such as Hashimotos thyroiditis or Grave’s disease). The two main types of thyroid antibodies are thyroid peroxidase and thyroglobulin antibodies.
What each lab means
- TSH: High TSH levels mean the thyroid gland is not making enough of this hormone (which happens in hypothyroidism), while low levels mean it is making too much (hyperthyroidism). However, it should always be checked within a larger context of thyroid labs.
- Free T4: High free T4 can indicate an overactive thyroid (hyperthyroidism) while low levels can indicate underactive thyroid function (hypothyroidism).
- Free T3: High free T3 also indicates overactive thyroid. Low levels may mean that your body isn’t converting T4 into T3 very well and may indicate hypothyroidism even if TSH and free T4 are within the normal range.
- Reverse T3: High reverse T3 may mean that not enough free T4 is being converted into free T3, and can cause symptoms of hypothyroid even if TSH and T4 are normal. Chronic stress and high cortisol levels can raise reverse T3.
- Thyroid antibodies: High levels of either lab indicate that the immune system is attacking the thyroid and can be a basis for diagnosing an autoimmune condition.
Because the thyroid plays so many important roles in the body, it’s super important to know your labs and understand what each of them mean. Be an advocate for yourself by asking your doctor for a full thyroid panel and explain the reasons why. For information about symptoms of thyroid issues, possible causes, and foods to focus on to help restore balance in your thyroid, check out our post here.