Graves’ Disease vs. Subacute Thyroiditis: What’s The Difference?

Most cases of hyperthyroidism are autoimmune in nature.  So when someone finds out that they have hyperthyroidism for the first time, there is a pretty good chance that they will be diagnosed with Graves’ Disease.  However, this isn’t always the case, as some people with hyperthyroidism have multinodular toxic goiter, which frequently doesn’t involve an autoimmune component.  And some people with hyperthyroidism have subacute thyroiditis.  And that will be the focus of this blog post, as I’ll be discussing the differences between Graves’ Disease and subacute thyroiditis.

With regards to the symptoms, both Graves’ Disease and subacute thyroiditis present with similar symptoms.  As a result, one usually can’t use the typical symptoms of hyperthyroidism to differentiate between the two conditions.  Here are some of the symptoms those with Graves’ Disease and subacute thyroiditis commonly experience:

• Elevated resting pulse rate
• Heart palpitations
• Tremors
• Weight loss
• Increased appetite
• Goiter
• More frequent bowel movements
• Sweating
• Hair loss

But are the symptoms of hyperthyroidism as severe in someone who has subacute thyroiditis when compared to someone who has Graves’ Disease?  The symptoms can be severe, as the resting heart rate can get very high, and on a blood test the thyroid hormone levels can be just as high as in someone who has Graves’ Disease.  In fact, over the years I’ve had a few Graves’ Disease patients who presented with what I would consider to be mild hyperthyroidism.  On a few occasions I have even worked with people who have subclinical Graves’ Disease.  In other words, they will have a depressed TSH with elevated thyroid stimulating immunoglobulins, but they will have normal thyroid hormone levels and/or won’t experience the hyperthyroid symptoms I listed above.

Two Main Types of Subacute Thyroiditis

1. Subacute granulomatous thyroiditis.  This is also known as De Quervain’s thyroiditis, and is very painful.  In fact, it is the most common cause of someone having a painful thyroid gland.

2. Subacute lymphocytic thyroiditis.  This typically doesn’t involve any pain, and is often mistaken for Graves’ Disease.

Both of these conditions seem to be caused by a viral infection of the thyroid gland.  This causes inflammation, which in turn damages the thyroid follicles, and this causes thyroid hormone to be released into the bloodstream, which in turn results in the symptoms of hyperthyroidism.  The hyperthyroidism usually lasts anywhere from a few weeks to a few months, and it is usually followed by a period of hypothyroidism that can last six months or longer, and in some cases can be permanent.

Three Ways To Differentiate Graves’ Disease From Subacute Thyroiditis

1. An elevation of TSH receptor antibodies.  Graves’ Disease is an autoimmune thyroid condition that is characterized by elevated TSH receptor antibodies.  Thyroid stimulating immunoglobulins are the most common type of TSH receptor antibody elevated in Graves’ Disease, and if someone with hyperthyroidism has these levels elevated then this confirms that they have Graves’ Disease, and not subacute thyroiditis.

2. The signs and symptoms of thyroid eye disease.  Some people with Graves’ Disease also have thyroid eye disease, which is when the immune system attacks the tissues of the eyes.  This can lead to symptoms such as eye pain, swelling, and/or bulging of the eyes, also known as exophthalmos.  And so if someone with hyperthyroidism has one or more of these signs/symptoms then in all likelihood they have Graves’ Disease.  Keep in mind that most people with thyroid eye disease have very high levels of thyroid stimulating immunoglobulins, and so if you have the signs and symptoms of thyroid eye disease I would definitely make sure to test the TSI levels.

3. An elevated radioactive iodine uptake test.  Many endocrinologists will recommend the radioactive iodine uptake test, which involves swallowing a very small dosage of radioactive iodine.  In most cases of Graves’ Disease the radioactive iodine uptake test will be elevated, while in subacute thyroiditis the uptake test will usually be low.

If someone has elevated thyroid stimulating immunoglobulins then there really is no good reason to do the RAI uptake test.  But how about if someone with hyperthyroidism tests negative for these antibodies, and doesn’t have the symptoms of thyroid eye disease?  Well, in this case one can make a better argument for getting this test, although I must admit that I’m still not a big fan of this test.

Treating Graves’ Disease vs. Subacute Thyroiditis

The conventional medical approach for treating Graves’ Disease usually consists of antithyroid medication, radioactive iodine, or thyroid surgery.  With subacute thyroiditis, since this usually leads to hypothyroidism, most medical doctors will manage the patient’s symptoms through antithyroid medication and/or beta blockers.  While Methimazole is a common choice for managing the hyperthyroid symptoms in Graves’ Disease, with subacute thyroiditis many medical doctors prefer to use beta blockers.  And the reason for this is because the person with subacute thyroiditis is likely to become hypothyroid within a short period of time, and if they are taking Methimazole then this will make them even more hypothyroid.  Of course taking the person off of the Methimazole will decrease the severity of the hypothyroidism, but many medical doctors still choose not to put these patients on antithyroid medication.

As for treating these two conditions naturally, the goal with Graves’ Disease is to detect and remove the autoimmune trigger.  This topic is too detailed to discuss here, but I have written numerous articles which discuss this, and I also regularly conduct webinars that focus on natural treatment methods for Graves’ Disease.  I will say that managing the symptoms is similar in both of these conditions, although as is the case with Graves’ Disease, antithyroid herbs such as bugleweed need to be used cautiously due to the person eventually becoming hypothyroid.  Motherwort might be a better option in those with subacute thyroiditis, although if this doesn’t help to lower an elevated heart rate then bugleweed can be used.  If this is the case then the person wants to make sure to carefully monitor their symptoms, and it probably would be a good idea to do a follow-up blood test within four weeks.

Since subacute thyroiditis is caused by a virus, it still makes sense to do things to improve the health of the immune system.  And the reason for this is because viruses usually can’t be eradicated, which means that a person can have subacute thyroiditis multiple times.  For more information on viruses I would refer to an article I wrote on viruses entitled “Which Viruses Can Trigger Thyroid Autoimmunity?”.

So hopefully you have a better understanding of the difference between Graves’ Disease and subacute thyroiditis.  Both of these conditions present with similar symptoms, including an elevated resting pulse rate, heart palpitations, weight loss, increased appetite, and frequent bowel movements.  Two main types of subacute thyroiditis include subacute granulomatous thyroiditis and subacute lymphocytic thyroiditis.  Three ways to differentiate Graves’ Disease from subacute thyroiditis include 1) an elevation of TSH receptor antibodies, 2) having the signs and symptoms of thyroid eye disease, and 3) having an elevated radioactive iodine uptake test.  With both Graves’ Disease and subacute thyroiditis, improving the health of the immune system is the key.