ThyroidWomen's Health

Hyperthyroidism: Symptoms and Treatment

Written by

Lauren Dobischok
2 June, 2023

Medically checked article All HOMED-IQ content is reviewed by medical specialists

The thyroid gland is a small butterfly-shaped organ located in the front of the neck. This organ makes and releases hormones that regulate body functions such as metabolism, energy production, body temperature regulation, digestion, and growth (Cleveland Clinic, 2022). The thyroid plays an essential role in many processes in the body, and an imbalance of thyroid hormones can cause unpleasant symptoms and health problems over time. In this article, we will explore the causes, symptoms, diagnosis, and potential treatment options for hyperthyroidism.

How does the thyroid work?

In addition to producing hormones, the thyroid also regulates how much of each hormone is released into the body. The process begins when the pituitary gland, located at the base of the brain, releases thyroid-stimulating hormone (TSH). TSH acts as a messenger, instructing the thyroid gland to produce and release hormones thyroxine (T4) and triiodothyronine (T3). The thyroid primarily produces T4, which is the inactive form of thyroid hormone. Once released into the bloodstream, T4 is converted into T3 by various organs and tissues. T3 is the active form of thyroid hormone that has a more direct impact on the body’s cells. Free T3 (FT3) and free T4 (FT4) are the forms of thyroid hormones that are not bound to proteins and are available for use by the body’s cells.

The thyroid gland responds to increased levels of TSH by creating more thyroid hormones, and conversely creates less thyroid hormones when TSH is lowered. An interruption in this balance can lead to either too much or too little thyroid hormones in the blood, leading to hyperthyroidism or hypothyroidism.

What is hyperthyroidism?

Hyperthyroidism is a health condition in which the thyroid gland is overactive, producing excessive amounts of T3 and T4. In contrast, hypothyroidism occurs when there is insufficient production of these hormones. An overproduction of thyroid hormones can speed up your body’s metabolism significantly, causing symptoms that affect the entire body.

Symptoms of hyperthyroidism

Since the thyroid controls multiple body systems,  hyperthyroidism can cause a range of symptoms affecting different parts of the body. Symptoms of hyperthyroidism can include:

  • Unexpected weight loss
  • Rapid or irregular heartbeat
  • Increased appetite
  • Thinning skin and brittle hair
  • Nervousness, anxiety, and irritability
  • Trembling in your hands and fingers
  • Sweating
  • Changes in menstrual patterns
  • Increased sensitivity to heat
  • Changes in bowel patterns, especially more frequent bowel movements
  • An enlarged thyroid gland (goiter)
  • Fatigue, muscle weakness
  • Difficulty sleeping 

Source: Mayo Clinic, 2022

Causes of Hyperthyroidism

Understanding the cause of hyperthyroidism is important for ensuring effective treatment and alleviating symptoms. Common causes of hyperthyroidism include:

  1. Graves’ Disease: This autoimmune disorder is the most common cause of hyperthyroidism. In Graves’ disease, the body’s immune system mistakenly attacks the thyroid gland, leading to overproduction of thyroid hormones.
  2. Overactive thyroid nodules: Also known as a toxic multinodular goiter, this condition is caused by noncancerous lumps or nodules in the thyroid gland called adenomas. If the adenomas produce too many thyroid hormones, hyperthyroidism can occur. 
  3. Thyroiditis: Inflammation of the thyroid is also called thyroiditis and can cause extra hormones stored in the thyroid to leak into the bloodstream. 
  4. Excessive Iodine Intake: Consuming large amounts of food or supplements containing iodine can cause hyperthyroidism in rare cases.
  5. Pituitary Adenomas: Although rare, tumors in the pituitary gland can cause overproduction of thyroid-stimulating hormone (TSH), which stimulates the thyroid gland to produce more hormones.
  1. Taking too much thyroid hormone: Individuals who are prescribed thyroid replacement medications for an underactive thyroid (hypothyroidism) can cause hyperthyroidism if the prescribed medication dose is too high. If you take thyroid medications and begin to experience symptoms of hyperthyroidism, speak to your healthcare provider about adjusting your dose.

Source: Penn Medicine, 2022

Diagnosing hyperthyroidism

Getting a hyperthyroidism diagnosis begins with a trip to the doctor. They will ask questions about your medical history, perform a physical examination, and carry out other tests, such as blood tests to measure TSH, T3, and T4 levels or a thyroid scan. 

If you would like to first check your thyroid hormones without visiting a doctor, try Homed-IQ’s home Thyroid Blood Test. This test is the same as a thyroid blood test performed in a clinic or doctor’s office, but the sample is taken at home using a finger prick before being sent to a certified laboratory. If the test result is abnormal, the laboratory report can be brought to your GP for follow-up testing and treatment.

Treatment of Hyperthyroidism

Treatment for hyperthyroidism aims to return the production of thyroid hormones to normal, alleviate symptoms, and manage potential complications. Common treatment options include:

  1. Anti-thyroid Medications: Drugs like methimazole can help prevent the thyroid from overproducing hormones, easing symptoms of hyperthyroidism.
  2. Radioactive Iodine: Taken orally, this treatment causes the thyroid gland to shrink and symptoms to subside within a few months. Over time, this treatment can cause the thyroid to become underactive (hypothyroidism). Because of this, thyroid replacement hormones may be required over time.
  3. Beta-Blockers: These medications don’t reduce thyroid hormones, but can alleviate symptoms of hyperthyroidism like rapid heart rate, tremors, and anxiety.
  4. Thyroid Surgery (Thyroidectomy): In rare cases where anti-thyroid medication or radioactive iodine therapy cannot be used, part or all of the thyroid gland may need to be removed. People who have their thyroid removed require lifelong thyroid replacement medication.

Source: UCSF, 2023

If you are diagnosed with hyperthyroidism, discuss the risks and benefits of all treatment options with your healthcare provider. They can help you make an informed decision that alleviates symptoms and fits your lifestyle. 


Cleveland Clinic. (2022, June 7). Thyroid.’s%20main%20job%20is%20to%20control%20the%20speed%20of,can%20impact%20your%20entire%20body.

Mayo Clinic. (2022, November 30). Hyperthyroidism – Symptoms and causes.

Penn Medicine. (2022, September 12). Hyperthyroidism (Overactive Thyroid).

University of California San Francisco. (2023). Hyperthyroidism Treatment. UCSF Health.

About the author

Lauren Dobischok

Lauren is a health scientist and science communicator currently living in the Netherlands. Originally from Canada, she completed a Research Master’s in Health Sciences at the Netherlands Institute of Health Sciences at Erasmus University Rotterdam (NIHES) with a specialisation in epidemiology. Prior to her master’s degree, she completed a Bachelor’s degree in Health Sciences at Simon Fraser University. With a background in public health, her goal is to create accurate scientific content that is easy to understand and empowers people to make informed decisions. Within Homed-IQ, Lauren works as a Product Developer and Content Lead, working closely with physicians and scientists on medical devices for Homed-IQ’s new products and written communications.