thyroid gland with arrow pointing upwards and text bubble saying what is hyperthyroid disease?

Hyperthyroidism is the abnormally high activity of the thyroid gland. Since the thyroid gland serves so many functions, signs and symptoms are varying and can affect many aspects of human health. Hyperthyroidism is diagnosed by signs and symptoms and confirmed with blood tests and sometimes scans.

It affects approximately 2% of women and 0.2% of men.

A Review of Normal Thyroid Function

Thyroid function is controlled by a variety of glands and hormones, as depicted in the figure below.

For more information, please click here for a full detailed explanation.

a full schematic of thyroid physiology, including hypothalamus, anterior pituitary gland, thyroid gland and the hormones TSH, T3 and T4


As mentioned previously, hyperhyroidism describes high thyroid activity. This means that T3 and T4 are having an elevated effect throughout the body.

The image below depicts how high functioning thyroid may look on blood work. High T3 and T4, as well as a low TSH are commonly seen in patients with high thyroid activity.

thyroid physiology involved in hyperthyroidism showing T3 and T4 hormones have increased expression while TSH drops

Causes of Hyperthyroidism [15]

There are various causes of excessive thyroid activity. Anyone diagnosed with hyperthyroidism must ensure their health care provider has investigated the following, as treatment options vary drastically from one cause to another.

There are 2 main categories of hyperthyroidism: stimulatory and non-stimulatory.

Stimulatory Causes: positive radioactive iodine scan

  1. Graves' Disease (60-80%) of cases
  2. Trophoblastic Tumors activate TSH receptors via HCG (Choriocarcinoma)
  3. TSH-secreting Pituitary Adenoma

Non-Stimulatory Causes

  1. Toxic Multinodular Goiter (5%, especially elderly people in Iodine deficient regions)
  2. Toxic Thyroid Adenoma (Plummer's Disease)
  3. Exogenous Thyroid hormone source
  4. Thyroiditis (common)
  5. Subacute Thyroiditis
  6. Acute Thyroiditis (Bacterial Infection)
  7. Postpartum Thyroiditis (Lymphocytic Thyroiditis)
  8. Tumors (rare)
  9. Metastatic Follicular Thyroid Cancer
  10. Ovarian Cancer producing Thyroxine (struma ovarii)
  11. Medication-Induced Hyperthyroidism

Combined Stimulatory and Non-Stimulatory Causes: (positive Radioactive Iodine scan)

  1. Nodular Goiter with superimposed stimulation

Symptoms of Hyperthyroidism

Since thyroid function controls every aspect of your body, symptoms can be quite broad. In fact, none of these are specific to hyperthyroidism, which is why a thorough history and medical history, as well as lab testing is crucial.

Neuropsychiatric symptoms

  • Nervousness or alertness
  • Emotional lability (Anxiety, Irritability or even Psychosis)
  • Proximal Muscle Weakness
  • Insomnia

Adrenergic symptoms

  • Palpitations
  • Tremor
  • Frequent Bowel Movements or Diarrhea
  • Excessive Sweating
  • Heat intolerance


  • Weight loss despite increased appetite (hypermetabolism)
  • Oligomenorrhea or amenorrhea
schematic of the symptoms of hyperthyroidism, including neuropsychiatric, generalized and adrenergic


Hyperthyroidism is a condition characterized by excessive thyroid function. Since the thyroid serves so many functions throughout the body, heightened thyroid function will present with a variety of signs and symptoms. Treatment varies from person to person.

Book in with your naturopath to discuss the unique approaches to treating the various forms of hyperthyroidism.


Interested in learning more?

Read on in our series of articles on Thyroid Health!

About the Author - Dr. Johann de Chickera

man facing camera

Dr. Johann is a fully licensed Naturopathic Doctor. His approach emphasizes the importance of living a healthy lifestyle and improving one’s health naturally. Dr. Johann obtained a Doctor of Naturopathy at the Canadian College of Naturopathic Medicine (CCNM). Education at CCNM is a vigorous four years, with a curriculum involving biomedical sciences, physical diagnosis, clinical nutrition, traditional Chinese medicine and acupuncture, botanical (herbal) medicine, physical medicine, homeopathy and lifestyle management.

While Dr. Johann has a general practice, he focuses on fertility, hormonal imbalances, gut health, and autoimmune disease.

To book in please call us at (519) 442-2206 or click here.

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