Medically reviewed by Rosanna Sutherby, PharmD on October 13, 2020. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.
If you’ve been experiencing symptoms like nervousness, fatigue, or heat sensitivity—to name just a few examples—you might be wondering if it could have something to do with your thyroid function. These and other symptoms are all possible consequences of an overactive thyroid. So if you’re interested in learning more about common overactive thyroid symptoms, you’ve come to the right place. Read on to discover what the thyroid does in the body, signs and symptoms of an overactive thyroid (plus possible causes), how the condition is diagnosed, and more.
Check if your thyroid hormones are balanced from the convenience of home with the Everlywell at-home Thyroid Test.
The thyroid is a small gland located right below the larynx (the voice box) at the base of the neck. Because it’s involved in many body processes and functions (such as metabolism) through the controlled release of hormones, this butterfly-shaped gland plays a key role in one’s overall health.
The thyroid produces two main hormones—thyroxine (T4) and triiodothyronine (T3)—which circulate throughout the bloodstream, acting as “chemical messengers” that help regulate a wide variety of processes in the body. For instance, metabolism, body temperature, and heart rate are all influenced by thyroid hormones.
Because the thyroid is a crucial part of the body, when it malfunctions—becoming overactive (hyperthyroidism) or underactive (hypothyroidism)—your health can suffer and you may experience a variety of symptoms. If the thyroid gland is overactive, it produces an excessive amount of thyroid hormones—disturbing the thyroid’s regulatory function, which relies on balanced thyroid hormone levels. On the flip side, if the thyroid is underactive, that means it’s not making enough hormones.
In this article, we’ll focus on symptoms associated with an overactive thyroid. (Related: Hypothyroidism vs. hyperthyroidism: the key differences explained)
From weight loss to nervousness or anxiety, there are many different overactive thyroid symptoms someone can potentially experience. So, without further ado, here are 23 common signs and symptoms to consider if you suspect your thyroid gland has shifted into overdrive. List of overactive thyroid symptoms to be aware of.
Note: Keep in mind that these signs and symptoms can occur for reasons other than an overactive thyroid—so if you’re experiencing any of the above, discussing it with your healthcare provider is one of the best next steps to take.
Now that you’re more familiar with overactive thyroid symptoms, you may be wondering what causes a thyroid problem like this in the first place. Here are several possible reasons for an overactive thyroid.
Graves’ disease is the most common cause of hyperthyroidism (another term for overactive thyroid) in the United States. It’s estimated that approximately 3 in 4 people with an overactive thyroid have Graves’ disease—an autoimmune condition that involves one’s own immune system attacking the thyroid gland, causing it to become overactive.
The precise cause of this autoimmune disease is not yet known; however, what we do know is that it commonly runs in families. It’s also known that, in some cases, Graves’ disease can affect other parts of the body—not just the thyroid gland—such as skin and eyes. Graves’ eye disease (also known as Graves' ophthalmopathy or Graves' orbitopathy) may occur in 25-50% of people diagnosed with Graves’ disease, according to some estimates. Symptoms of Graves’ eye disease can include:
High iodine intake can lead to excess thyroid hormone production. This can occur due to high dietary consumption of iodine (by eating foods rich in iodine, such as kelp). This can also come as a result of taking medication that contains iodine (such as certain medications that are prescribed to help control an irregular heartbeat).
Note: Be sure to always consult with your healthcare provider first before making any changes to your medication regimen.
Pituitary adenomas are benign tumors that affect the pituitary gland. The pituitary gland is located at the base of the brain and secretes hormones that influence thyroid hormone production levels.
In rare cases, a cancerous tumor in the thyroid affects the body’s production of thyroid hormones.
Also known as toxic adenoma, toxic multinodular goiter, or Plummer's disease, this type of hyperthyroidism happens when a benign tumor in the thyroid produces too much T4. The thyroid may also become enlarged.
If lumps, or nodules, develop on the thyroid, this can lead to hyperthyroidism. These nodules are often non-cancerous, but the thyroid tissue they contain can cause the body to produce more thyroid hormones than necessary.
Thyroiditis refers to inflammation of the thyroid (this sometimes occurs shortly after pregnancy, for example), which may result in the overproduction of thyroid hormones.
An overactive thyroid is typically diagnosed by a healthcare provider based on an evaluation of factors such as symptoms, medical history, and results from a blood test (known as a thyroid function test).
This test uses a blood sample to measure the levels of the following hormones:
Low TSH levels and high levels of T3 and/or T4 may indicate an overactive thyroid.
A healthcare provider may also recommend a blood test that checks for thyroid antibodies. Thyroid antibodies are commonly found in individuals who have Graves' disease.
An additional blood test called erythrocyte sedimentation rate (ESR) may also be conducted to look for inflammation in the body. Inflammation of the thyroid gland may lead to thyroiditis, as mentioned above. Additionally, a thyroid scan—also called nuclear medicine thyroid imaging—might be done to look for thyroid nodules.
Our Thyroid Test lets you easily check your thyroid hormone levels from the convenience of home, plus a type of thyroid antibody known as TPOab (thyroid peroxidase antibody).
What it measures:
TSH is the hormone responsible for controlling hormone production by the thyroid gland. It’s considered one of the most sensitive markers for screening for thyroid conditions.
Our test measures these key thyroid hormones so you can see whether your levels are low, normal, or high when compared to the reference range.
TPOab can bind to certain thyroid enzymes, thereby suppressing thyroid function. TPOab levels are often elevated in Hashimoto's disease, the most common type of hypothyroidism (underactive thyroid) in the United States.
If you experience overactive thyroid symptoms and are diagnosed with hyperthyroidism, it can help to know that effective treatments do exist (and should be discussed with your healthcare provider). Possible treatments include the following.
Thionamides keep your thyroid from producing excess hormones and are often used as a treatment for an overactive thyroid. The main types are carbimazole and propylthiouracil. A beta-blocker may also be given to help relieve your symptoms.
Some people may need to take medicine for years (or throughout their entire life), though others may be able to stop eventually once their thyroid hormone levels are under control.
Radioactive iodine treatment is a type of radiotherapy that kills cells in the thyroid gland to curb hormone production. Some people need only one treatment.
If you suffer from severe eye problems because of your thyroid, your thyroid is swollen, or your overactive thyroid symptoms keep coming back, a healthcare provider may recommend a surgical procedure to remove some or all of your thyroid.
Check your thyroid hormone levels from the convenience of home with the Everlywell Thyroid Test.
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