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In this lesson we’re going to talk about hyperthyroidism. You can already start to guess what this is by the name. Hyper always means high or excess, and obviously we’re referring to the thyroid gland.
So, hyperthyroidism is a condition of excess secretion of thyroid hormones, we’ll see increased levels of T3, T4, and Free T4 in the blood. We’ll also see decreased levels of TSH, or Thyroid Stimulating Hormone. Why is that? Well, let’s review how these hormones get secreted. The hypothalamus in the brain releases Thyrotropin Releasing Hormone, which goes to the pituitary gland and tells it to release Thyroid Stimulating Hormone. TSH goes to the Thyroid gland to tell it to secrete more thyroid hormones. Then, when the levels are high enough, the body sends a signal back to the hypothalamus to tell it to stop. That’s called a negative feedback loop. So, when something happens that causes these levels to be elevated, that means TSH secretion will decrease significantly. Now, the most common cause is Grave Disease, but also a tumor on any of those three glands could cause over secretion of TSH or these thyroid hormones. It could also simply be due to an overdose of thyroid medication. So, what does this do? Well…it’s excessive thyroid hormone action. The thyroid hormones are responsible for increased metabolism, growth & development, and increased effect of catecholamines like epinephrine. So, the biggest thing we see is an increased metabolic rate.
So…any time you think hyperthyroid, I want you to think hypermetabolic. Think about how you’d feel if you went and ran 10 miles right now. You’ll be hot, Your heart rate and blood pressure will go up. You may have palpitations and be shaky. And, if you’re anything like me, this 10-mile run will also make you emotional unstable and super agitated! And, of course if you do this 10 mile run repeatedly, you’ll lose weight, right? It’s all due to this hypermetabolic state. We’ll also see patients develop goiter, which is an enlarged bulge in the neck due to the overactive thyroid.
The other thing we see in hyperthyroidism, especially Graves’ Disease, is exophthalmos or these bulging eyes and blurry vision. This is like the look on my face when someone tells me I have to run 10 miles! It also causes heat intolerance. I mean, if you just ran 10 miles and you’re hot and sweaty, the last thing you want is a hot shower or a hot bath. You want to cool off and stay cool, right? Now, the other problem we see is that with this crazy high metabolism, the body starts to ignore some more non-vital functions. Their hair begins to thin, their libido decreases, and women will stop having periods. Think about young gymnasts who work out so much and they’re so hypermetabolic that they never have periods.
Then, as with most diseases, there’s a possibility for acute exacerbation, in this case known as Thyroid Storm or Crisis. They’ll be febrile, tachycardic, and hypertensive and can possible have tremors and seizures as well.
So how do we manage these patients? Well we want to provide rest and a cool, quiet environment and cardiac monitoring. We also want to make sure the patient has a patent airway, especially with the possibility of goiter and that neck swelling. We’ll provide eye protection for exophthalmos like eye drops. As far as medications, we can give antithyroid meds like propylthiouracil or methimazole or we can give radioactive iodine 131. In a functioning thyroid gland, we’ll see uptake of radioactive iodine so we can see it on a scan. With radioactive iodine 131, specifically, it will be taken up by the thyroid and it will actually destroy some of those thyroid cells so that will help decrease the overall levels of thyroid hormones. We do need to make sure this doesn’t shift them all the way into hypothyroidism. We’ll talk more about hypothyroidism in the next lesson.
The patient also has the option for surgical removal or a thyroidectomy. Post-op we want to monitor their airway because they could have swelling or obstruction. Listen for stridor or possibly dysphagia. We usually have tracheotomy equipment ready at the bedside. We want to keep them upright, assess for bleeding, and have them avoid talking for a while to protect the surgical site. We also want to monitor for hypocalcemia. You see, the thyroid hormone normally secretes calcitonin to increase calcium levels. Without it, our calcium levels can drop, so we make sure to have calcium gluconate available in case we need it.
Our priority nursing concepts for patients with hyperthyroidism are going to be hormone regulation, thermoregulation, and nutrition. With that hypermetabolic state we really need to make sure they’re getting enough calories in and we’re monitoring for and preventing thyroid storm. Make sure you check out the care plan attached to this lesson for more detailed nursing interventions and rationales.
So, let’s recap. Hyperthyroidism is a state of excessive secretion of thyroid hormones, so we see excess T3, T4, and free T4 levels and decreased TSH levels. It could be caused by Graves Disease or tumors of the hypothalamus, pituitary, or thyroid, or by overdose of thyroid medications. Remember when you think hyperthyroid, I want you to think hypermetabolic. Their blood pressure, heart rate, and temperature all go up and they might even be shaky or agitated. We want to give antithyroid meds and possibly radioactive iodine, but if those don’t work, the patient may require a thyroidectomy. That will make them hypothyroid, so make sure you check out that lesson as well!
So those are the basics of hyperthyroidism, make sure you check out all the resources attached to this lesson to learn more. Now, go out and be your best self today. And, as always, happy nursing!