Med-Surg Endocrine System, part 7: Thyroid Panel and Blood Glucose Labs
by Cathy Parkes August 06, 2020 Updated: December 07, 2022 3 min read 1 Comment
Throughout the Medical-Surgical Nursing series on the Endocrine system, you will learn lab values that are important for diagnosing and treating diseases. This video and article cover the most important lab value ranges (in the Endocrine system) that you definitely want to make sure you know for your exams!
These ranges are covered in our Medical-Surgical Flashcards (Endocrine system) as well as our Lab Values flashcards. The Lab Values flashcards provide a more in-depth review of these values.
NOTE: Lab values vary slightly from one source to another. Therefore, your textbook or professor may have slightly different lab value ranges from the lab value ranges shown here. On nursing exams, if you are given a lab value that is out-of-range, it will typically be VERY out-of-range. So, slight differences in expected lab value ranges should not impact your ability to recognize out-of-range values on exams.
Thyroid panel expected values
A thyroid panel is a group of blood tests that may be ordered to evaluate the function of the thyroid gland. This can help evaluate thyroid function and diagnose thyroid disorders. Tests that measure the level of thyroid hormones are also known as thyroid function tests. These tests are performed using a blood sample.
T3 and T4 are thyroid hormones that regulate metabolism and growth. We cover these in more detail in video 3 of this Endocrine series.
T3 normal range
The expected range for T3 in a thyroid panel is 70 - 204 ng/dL.
Easy way to remember the normal range for T3
T3 reminds you of “times three.” If you can remember 70, then 70 x 3 = 210, which is approximately the upper end of the range!
T4 normal range
The expected range for T4 in a thyroid panel is 4 - 12 mcg/dL.
Easy way to remember the normal range for T4
Cathy’s husband is obsessed with the Terminator movies.
My husband has watched Terminator at least 4-12 times.
Thyroid-stimulating hormone (TSH)
TSH is a hormone produced by the anterior pituitary gland, and it regulates the thyroid gland’s production of T3 and T4. This process is covered in more detail in our video on Negative Feedback Mechanisms.
TSH normal range
The expected range for TSH in a thyroid panel is 0.5 - 5.0 mU/L.
Easy way to remember the normal range for TSH
If you touch my “tush” again, I will slap you with all 5fingers.
Diseases and disorders related to T3, T4, and TSH
Low levels of T3, T4 combined with high levels of TSH can indicate primary hypothyroidism. Low levels of all three hormones can indicate secondary or tertiary hypothyroidism.
Myxedema coma is a life-threatening complication with excessively low levels of thyroid hormones.
High levels of T3, T4 combined with low levels of TSH can indicate primary hyperthyroidism. High levels of all three hormones can indicate secondary or tertiary hyperthyroidism.
Thyroid storm (thyrotoxicosis) is a life-threatening complication with excessively high levels of thyroid hormones.
Secondary or tertiary hypothyroidism
Secondary or tertiary hyperthyroidism
Blood glucose lab values
Blood glucose expected ranges are very important to know in your nursing studies and practice, because diabetes is so prevalent. These are values you will encounter often on exams and in a clinical setting.
Fasting blood glucose expected range
If your patient has a fasting blood glucose test, we would expect to see a value under 100 mg/dL.This test performed on an empty stomach (fasting), usually first thing in the morning.
2 hour oral glucose tolerance test (OGTT) expected range
If a patient has a two-hour oral glucose tolerance test, then we would expect a value under 140 mg/dL. This test measures a patient’s blood sugar levels once, then they drink a glucose solution, and their blood sugar levels are measured again two hours later. The point of this test is to see how the body processes sugar.
HgbA1C expected range
If your non-diabetic patient gets their HgbA1C level drawn, we would expect a value under 6%. The goal for a patient with diabetes is to have an HgbA1C under 7%.
Diseases and disorders related to blood glucose
You might be able to guess this one...diabetes! Diabetes Mellitus can be diagnosed using these guidelines.
Hypoglycemia is a blood glucose level under 70 mg/dL. Diabetic ketoacidosis (DKA) is a life-threatening diabetes complication with blood glucose over 300 mg/dL. Another serious complication is hyperglycemic hyperosmolar state (HHS), and that is with blood glucose levels over 600 mg/dL.
Remembering these labs will be key for any Medical-Surgical Nursing exam. The Medical-Surgical Nursing video series is intended to help RN and PN nursing students study for nursing school exams, including the ATI, HESI and NCLEX.
In this video we are going to briefly go over the lab values that I feel are important to know for the endocrine system. I would really concentrate on knowing the values associated with the thyroid panel, so T3, T4 and TSH, and then I would also know your blood glucose levels.
Let's start with T3. So T3 should be between 70 and 204, and the way I remember this range is T3 reminds me of times 3. So if you take 70 times 3, that gives you 210, which is kind of the upper end of that range. So if I can remember 70, and if I look at T3, then I know to multiply that times 3 to get 210 as the upper range. So this trick, along with others, is in my Lab Values deck, if you're interested.
T4. T4 should be between 4 and 12, and the way I remember this is that my husband is obsessed with Terminator, or at least used to be, and I've probably been forced to watch T4, or Terminator 4, between 4 and 12 times, and that's probably not an exaggeration at all. At least I've watched part of it 4 to 12 times, because I'm usually asleep for a good bit of it, so but yeah, 4 to 12 times, not kidding. So that's how I remember T4.
TSH. TSH reminds me of tush, right? So kind of missing the U but it looks like tush. The normal range for TSH is between 0.5 and 5, so it's roughly up to 5. So the way I remember this is if you touch my tush, again, right, my booty, I am going to slap you with all 5 fingers. So that helps me remember that when we're talking about TSH, the normal range is up to 5, 5 fingers. Okay. I hope you're enjoying my silly, little ways to remember these things.
Let's talk about blood glucose.
If your patient has a fasting blood glucose, we would expect them to have a value under 100. If they have a value over 100 for a fasting blood glucose, then we would be concerned for prediabetes or diabetes.
If a patient has a two-hour oral glucose tolerance test, then we would expect a value under 140.
And then if they get their HGB A1c level drawn, we would expect that percentage to be under 6, okay?
When we talk about diabetes in an upcoming video, if a patient has diabetes, we're going to manage their progress at controlling their blood glucose levels with that HGB A1c value. And if they keep it under 7, then that's usually good enough if the patient is diabetic.
But if we're talking about the general population and someone who does not have diabetes or at least not diagnosed diabetes, we would expect that A1c to be under 6.
Hopefully that's helpful. We will pick it up with endocrine disorders in my next video. Thank you so much for watching!
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October 19, 2020
more knowledge and inputs big help
Thank you so much