What are the symptoms of hyperthyroidism?

Symptoms of hyperthyroidism include: Racing heart rate, palpitations, anxiety, insomnia, nervousness, weight loss with increased appetite, excessive sweating / heat intolerance, muscle weakness, and abnormal menstrual cycles in premenopausal women.

Hyperthyroidism (Overactive Thyroid) Symptoms, Diagnosis and Pregnancy | Saint John’s Cancer Institute

What is Hyperthyroidism?

Hyperthyroidism is what happens when your thyroid gland is producing too much thyroid hormone and your body is running on overdrive. Hyperthyroidism is more common in women, but the reasons are unknown. The symptoms of an overactive thyroid, regardless of the cause, are basically the same, but hyperthyroidism treatment recommendations may vary depending on the diagnosis.

Graves’ Disease

Graves’ Disease is an autoimmune condition and the most common cause of an overactive thyroid. Thyroid antibodies attack your thyroid gland so that the body’s immune system overstimulates the thyroid gland to produce excessive amounts of thyroid hormone.

Subclinical Hyperthyroidism

Subclinical Hyperthyroidism is when your labs are mildly abnormal but you do not experience any symptoms. Depending on your age, other medical problems, and labs values, this may or may not need treatment.

The most common hyperthyroidism symptoms include:

Racing heart rate
Palpitations
Anxiety
Insomnia
Nervousness
Weight loss with increased appetite
Excessive sweating/heat intolerance
Muscle weakness
Abnormal menstrual cycles in premenopausal women.

Other hyperthyroidism (overactive thyroid) symptoms may include:

Abnormal blood pressure
Heart arrhythmias

Graves’ disease symptoms may also include:

Eye problems such as inflammation, swelling, and bulging of the eyes
Rare skin disease in the form of reddish, lumpy thickening on the shins

The best test to diagnose an overactive thyroid is a blood test called TSH (thyroid stimulating hormone).

TSH will be low if the thyroid is working too much.

If your TSH is found to be abnormally low (giving you a presumptive diagnosis of hyperthyroidism), other blood tests may include:

FT4 (free T4)
TT3 (total T3)
Thyroid antibodies (TSI, TRAB) – are useful in Graves’ disease diagnosis and monitoring of Graves’ disease treatment

If a thyroid nodule is palpated and you have hyperthyroidism, your thyroid endocrinologist may order a thyroid ultrasound or a thyroid uptake scan.

Hyperthyroidism can be treated with anti-thyroid medication, radioiodine treatment (RAI), or thyroid surgery (thyroidectomy).

Most patients will be started on anti-thyroid medication initially to control symptoms of hyperthyroidism. Your physician will then discuss with you the risks and benefits of all three options and help you decide which is most appropriate to achieve a long-term cure. Patients with Graves’ eye disease should be seen by an ophthalmologist for further evaluation.

Can diet or any complementary therapies treat an overactive thyroid?

In general, there are no randomized controlled trials demonstrating that diet or any complementary therapies significantly alter thyroid function or successfully treat thyroid cancer, hypothyroidism or hyperthyroidism.
However, there are some programs that discuss ‘thyroid healthy’ foods and lifestyles. In general, most cause no harm, but they also have no proven benefit.

Hyperthyroidism and Pregnancy

The levels of thyroid hormone circulating in the body fluctuate normally during pregnancy. However, maternal hyperthyroidism during pregnancy develops in about 1/1,500 pregnancies, most commonly from Graves’ disease.

Hyperthyroidism during pregnancy needs to be treated and addressed to prevent complications such as early labor or pre-eclampsia in the mother and prematurity, fast heart rate, congenital defects, or neonatal hyperthyroidism in the fetus.

Treatment during pregnancy depends on the severity of the disease. Mild hyperthyroidism is many times only closely monitored whereas moderate or severe disease will be treated with antithyroid-medications or rarely surgery. Hyperthyroidism can also occur in the postpartum period and when it does, it is usually followed by hypothyroidism.