Thyrotoxicosis: Definition, Symptoms, Causes, And Treatment

Your thyroid gland plays a major role in ensuring that your body is functioning optimally by regulating the production of thyroid hormones (hyperthyroidism). Having a properly functioning thyroid gland is important for your overall health. If it is not working properly, you can develop thyrotoxicosis.

Read on to find out exactly what the thyroid does in your body and how to prevent and treat thyrotoxicosis.

Role of the thyroid gland

The thyroid is a gland located in your neck that is responsible for producing the two thyroid hormones: triiodothyronine (T3) and thyroxine (T4). Together, these hormones help regulate your body's metabolism.

When your body needs more energy, the thyroid gland produces more of these hormones, which speeds up your metabolism and causes your body to process energy faster.

To do this, the thyroid gland gets help from the pituitary gland. Without the pituitary gland, the thyroid gland would have no way of knowing when your body needs more energy.

The pituitary gland sends this message to the thyroid gland by producing a hormone that stimulates thyroid hormone production. When this happens, the thyroid gland uses iodine to produce thyroid hormones.

Thyrotoxicosis

The thyroid and pituitary glands are engaged in a constant balancing act to keep your body’s metabolic rate at just the right level to meet your day-to-day needs. The two glands work together to produce the correct number of thyroid hormones at any given time. Sometimes, however, the thyroid may produce the wrong quantity.

When your body has too many thyroid hormones (hyperthyroidism), thyrotoxicosis occurs.

Symptoms

Common symptoms of thyrotoxicosis include:

• Reduced heat tolerance

• Increased heart rate

• Heart palpitations

• Anxiety

• Fatigue

• Unexplained weight loss

• Muscle weakness

• Diarrhea

• Hair loss

Causes

Thyrotoxicosis is a condition in which you have too many thyroid hormones in your body, which can be caused by a range of factors.

Excess iodine

The thyroid gland uses iodine to produce thyroid hormones, but consuming too much iodine in your diet can result in hyperthyroidism.

Autoimmune disorders

Graves’ disease is a common cause of thyrotoxicosis. This is a condition where your immune system attacks the thyroid, causing it to become overactive.

Thyroiditis

Thyroiditis is the general term for inflammation of the thyroid gland. There are many causes for this condition that can result in an overactive thyroid, with viral infections being the most common.

However, thyroiditis can also be caused by autoimmune disorders, fibrosis of the thyroid, or certain medications.

Treatment for hypothyroidism

Hypothyroidism is the exact opposite of hyperthyroidism. When you have hypothyroidism, your thyroid doesn't produce enough thyroid hormones. This condition can also be caused by another autoimmune disorder, such as Hashimoto's disease.

Doctors prescribe synthetic thyroid hormones to compensate for your body not producing enough thyroid hormones. However, taking too much hypothyroid medication can result in excess T3 and T4. This can cause you to swing the other way and develop hyperthyroidism.

Hamburger thyrotoxicosis

As many animals produce the same thyroid hormones as humans, it is possible to develop thyrotoxicosis if you consume beef from cattle with excessive thyroid hormones. This is a condition known colloquially as “hamburger thyrotoxicosis.”¹

Treatment

Treatment for thyrotoxicosis depends on the exact cause of the condition. If it was caused by overusing hypothyroidism medication, adjusting the medication can resolve the issue.

Similarly, hamburger thyrotoxicosis resolves itself once you remove the affected meat from your diet. However, if you have longer-lasting conditions such as Graves' disease, medical intervention will be necessary to help your body regulate the number of thyroid hormones it produces.

Common treatment options include the following:

Beta-blocker therapy

Even before the exact cause of your thyrotoxicosis is identified, you may be prescribed a beta-blocker to help treat the symptoms. A beta-blocker is a type of tablet medication.

Propranolol is a beta-blocker that is commonly prescribed for thyrotoxicosis. The purpose of this form of therapy is to alleviate symptoms of thyrotoxicosis. However, it is important to note that it does not reduce the number of thyroid hormones produced by the body.

Beta-blockers can help improve symptoms such as heart palpitations, tremors, anxiety, and sweating, which makes this a good option to use in conjunction with other treatments.

Thionamide drugs

Propylthiouracil and methimazole are thionamide drugs that are commonly prescribed to treat thyrotoxicosis. These medications reduce the production of thyroid hormones by the thyroid gland.

However, the risk of this treatment is that it can result in the thyroid gland not producing enough thyroid hormones.

Depending on your specific treatment plan, this side effect can be compensated for by continually adjusting the dosage or keeping the dosage high and using hormone replacement therapy to make up for the missing thyroid hormones.

Radioiodine therapy

As the thyroid uses the iodine consumed through your diet to produce thyroid hormones, your doctor may recommend you undergo radioiodine therapy. This form of therapy adds radiation to iodine, which you then ingest.

The radiation specifically targets iodine buildup in the thyroid gland by weakening it so it produces fewer thyroid hormones. However, the radiation is not strong enough to harm the rest of your body.

A risk of this treatment is that it can also result in the thyroid gland producing too few thyroid hormones, for which the only solution is taking synthetic thyroid hormone pills.

Thyroidectomy

A more invasive method of dealing with thyrotoxicosis is a partial or complete thyroidectomy. This procedure involves the partial or total surgical removal of the thyroid gland to reduce thyroid hormone production.

As with radioiodine therapy, this treatment will require you to take thyroid hormone medication for the rest of your life to counteract the lost thyroid function.

While radioiodine therapy and a thyroidectomy offer more permanent solutions to treating thyrotoxicosis, beta-blockers and thionamide drugs can be used to temporarily increase thyroid hormone production, as in the case of thyroiditis. This helps manage symptoms and tame the thyroid gland as the infection progresses.

Complications

Complications can arise as a result of both the failure to treat thyrotoxicosis and the treatment itself. Failing to treat thyrotoxicosis can be life-threatening.

As such, it is important to seek medical attention immediately if you believe you are suffering from the symptoms of thyrotoxicosis. Early detection enables early treatment so you can avoid any dangerous complications, which include the following:

Hypothyroidism

Hypothyroidism is a condition where the thyroid gland does not produce enough thyroid hormones, so treatment aims to restore normal thyroid function. However, hypothyroidism can be easier to regulate with thyroid supplementation.

Thyroid storm

When your thyroid gland produces too many thyroid hormones, you can develop a deadly condition called a thyroid storm². This is a severe medical condition that can occur when your body produces more thyroid hormones than it can handle.

Symptoms include a very high heart rate, fever, impaired liver function, features of cardiac failure, and agitation. A thyroid storm requires immediate medical attention.

Diagnosis

To diagnose you with thyrotoxicosis, your doctor will likely start by asking some medical questions to determine the possible cause. This is often followed by a physical examination of your neck to check for any enlargement of the thyroid gland.

The next step is for you to undergo tests to confirm a diagnosis of thyrotoxicosis. These include blood tests that allow your doctor to test the number of thyroid hormones in your system to see if the levels are too high.

You may also undergo an imaging test, such as an ultrasound, which enables your doctor to get a better look at the thyroid and check for enlargements or irregularities that may not have been detected during the physical exam.

The lowdown

Thyrotoxicosis refers to any condition where your thyroid gland produces too many thyroid hormones. When detected early, the condition is easy to treat. However, if left untreated or treated improperly, it can develop into a rare, life-threatening condition known as a thyroid storm that requires immediate medical attention.

If you have any of the symptoms of thyrotoxicosis discussed in this article, contact your doctor to seek diagnosis and treatment.