Symptoms of Thyrotoxicosis

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Excess amounts of thyroid hormones, like thyroxine (T4) and triiodothyronine (T3), can speed up your metabolism and result in symptoms of thyrotoxicosis

Common symptoms of thyrotoxicosis include weight loss, shakiness, anxiety, irritability, heat intolerance, sweating, menstrual problems, and heart palpitations. Symptoms vary from person to person and can range from mild to life-threatening, depending on the severity of the condition.

This article covers common and rare thyrotoxicosis symptoms, potential complications, and when to see your healthcare provider.

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Frequent Symptoms 

Mild thyrotoxicosis often does not cause symptoms. As the condition becomes more severe, common symptoms may occur, including:

People with autoimmune Graves’ disease may experience additional symptoms, including swelling of the fingertips, skin changes on the legs (e.g., redness, thickening), and eye problems, such as swelling, eye bulging, and dryness.

Rare Symptoms 

Rare symptoms of thyrotoxicosis include: 

Thyrotoxic periodic paralysis is associated with episodes of severe muscle weakness or paralysis. Episodes of muscle weakness tend to come and go and can last for a few hours or several days. The legs, hips, and shoulders are most commonly affected. These episodes are often triggered by rest after exercise or meals high in carbohydrates and sodium.


When left untreated, thyrotoxicosis can lead to serious health complications, including:

Thyroid storm: A rare but life-threatening emergency that requires immediate medical attention. Thyroid storm symptoms include accelerated heart rate, elevated blood pressure, and high body temperature. People who experience a thyroid storm may become agitated, confused, restless, sweat excessively, and become delirious.

Bone loss: An excess of thyroid hormones harms bone health and can accelerate bone loss, leading to weaker bones and an increased risk of fractures. Thyrotoxicosis increases the risk of developing osteoporosis, a loss of bone mineral density and bone mass.

Heart problems: High levels of thyroid hormones in the body are associated with an increased risk of cardiovascular issues, including an enlarged heart, arrhythmia (irregular heartbeat), angina (chest pain), high systolic blood pressure, and heart failure.

Thyroid eye disease: Early symptoms include itchy, watery eyes that feel gritty. Some people with thyroid eye disease also experience sensitivity to light, pain when moving the eyes, and swelling that gives the eyes a bulging appearance. As the disease progresses, vision impairment and difficulty closing or moving the eyes can occur. Thyroid eye disease is most common in people with Graves' disease.

When to See a Healthcare Provider

If you have symptoms of thyrotoxicosis, make an appointment with your healthcare provider. They will take your family and medical history and ask about your symptoms, including how long you've been experiencing them and how severe each symptom is.

Your healthcare provider will perform a physical examination to look for signs of hyperthyroidism (overactive thyroid) and thyrotoxicosis, such as rapid heart rate, high blood pressure, and dry skin. They will also examine your neck and palpate your thyroid gland to check for signs of tenderness, enlargement, or nodules. Blood tests may be required to check your thyroid hormone levels for an accurate diagnosis.

If you've been diagnosed with thyrotoxicosis, you will see your healthcare provider regularly to check your thyroid hormone levels and monitor your symptoms. You should see your healthcare provider if you develop new or worsening symptoms. They may adjust your medication or recommend another treatment to better manage your symptoms.

When to Seek Emergency Care

Call 911 or go to the nearest emergency room if you or a loved one has a fever, rapid heartbeat, chest pain, difficulty breathing, or a change in awareness. These symptoms indicate that you may be experiencing a thyroid storm or a cardiac event. 


Thyrotoxicosis is a rare condition associated with excess levels of thyroid hormones in the body. Common symptoms include weight loss, heart palpitations, heat intolerance, agitation, anxiety, tremors, menstrual problems, and sweating. Rare symptoms include hair loss, fertility problems, and thyrotoxic periodic paralysis.

Left untreated, thyrotoxicosis can lead to serious medical problems, including cardiac issues, bone loss, and potentially life-threatening thyroid storm. Talk to your healthcare provider if you have symptoms of thyrotoxicosis. The condition is highly treatable, and most people can manage symptoms and have a good quality of life with appropriate treatment. 

13 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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