Hyperthyroidism
Overview
Hyperthyroidism
Hyperthyroidism is also known as overactive thyroid, and sometimes hyperthyroidism is referred to as thyrotoxicosis. Hyperthyroidism causes an overproduction of hormones by the thyroid gland located at the front of the neck. Hyperthyroidism speeds up your body’s metabolism and can cause unintentional weight loss, a rapid or irregular heartbeat, and other symptoms. It can be a life-threatening disease if left untreated.
The butterfly-shaped thyroid gland releases hormones into the bloodstream. The bloodstream carries these hormones to every tissue in the body. Thyroid hormones regulate metabolism, help the body use energy, stay warm, and keep the heart, muscles, brain, and other organs working properly.
More than 3 million people each year in the United States are diagnosed with hyperthyroidism. Hyperthyroidism tends to run in families, and it is most common in females ages 50 and up. Additionally, those with a personal history of other autoimmune disorders such as type 1 diabetes, primary adrenal insufficiency, or pernicious anemia may also be more susceptible to hyperthyroidism.
Symptoms
Hyperthyroidism Symptoms
Hyperthyroidism can begin slowly, but in younger patients, these changes can be very sudden. Older adults are more likely to have no or subtle symptoms, such as an increased heart rate, heat intolerance, and a tendency to become tired during ordinary activities. Sometimes the first overt indication of hyperthyroidism is a protrusion or swelling at the base of your neck (goiter) since the other signs can be subtle. Or you might chalk most symptoms up to changes due to age.
Hyperthyroidism can mimic other medical conditions causing a wide variety of symptoms, making it difficult to diagnose. Some indications of hyperthyroidism include:
- Fatigue
- Hot flashes
- Thinning skin
- Burst of energy
- Protruding eyes
- Difficulty sleeping
- Increased appetite
- Increased sweating
- Nausea or vomiting
- High blood pressure
- Brittle hair or hair loss
- Shaking hands (tremors)
- Anxiety and nervousness
- Irritability and restlessness
- Increased sensitivity to heat
- Breast development in men
- Swollen thyroid gland (goiter)
- Rapid heartbeat (tachycardia)
- High blood pressure
- Brittle hair or hair loss
- Shaking hands (tremors)
- Anxiety and nervousness
- Irritability and restlessness
- Increased sensitivity to heat
- Breast development in men
- Swollen thyroid gland (goiter)
- Rapid heartbeat (tachycardia)
Grave’s Disease
Grave’s Disease (also known as Basedow’s Disease) is the most common form of hyperthyroidism. In Grave’s disease, the eyes may look enlarged, bulge, or protrude. When this happens, it is known as Grave’s Ophthalmopathy, and smokers are particularly susceptible.
Symptoms of Grave’s Ophthalmopathy include:
- Excessive tearing or discomfort in one or both eyes
- Dry eyes
- Protruding eyeballs
- Light sensitivity, blurry or double vision, inflammation, or reduced eye movement
- Red or swollen eyes
Diagnosis
Hyperthyroidism Diagnosis
Diagnosis of hyperthyroidism begins with a doctor’s visit, where you will receive an examination, have your medical history and your family’s medical history taken, and discuss your symptoms. Your doctor may check your thyroid gland and look for other indications. Still, since hyperthyroidism can mimic other medical conditions causing a wide variety of symptoms, it can be challenging to diagnose. A simple blood test may be the next step.
It is essential to let your doctor know of any medicines, vitamins, or supplements you are taking because some, like biotin, can affect your test results.
Blood Tests
to check the complete blood count (CBC), cholesterol, sugar levels, thyroid-stimulating hormones (TSH), and thyroxine. Blood tests also measure levels of thyrotropin receptor antibodies (TRAbs). High levels of thyroxine and low or nonexistent amounts of TSH indicate an overactive thyroid. If blood tests indicate hyperthyroidism, your doctor may recommend one or more of the following tests to help determine the cause of your overactive thyroid.
Radioiodine Uptake Test (thyroid uptake test)
to measure how much iodine your thyroid absorbs by taking a small dose of radioactive iodine. A high absorption rate indicates your thyroid gland produces too much thyroxine, suggestive of Grave’s disease or hyperfunctioning thyroid nodules. A low absorption rate suggests that the thyroxine stored in the gland is leaking into the bloodstream, which may mean you have thyroiditis.
Thyroid Scan
to show where radioactive iodine collects in your thyroid. A special camera produces images of your thyroid gland showing how iodine collects in your thyroid. This test is usually performed together with the thyroid uptake test.
Thyroid Ultrasound
to see if there are any thyroid nodules. This test uses high-frequency sound waves to produce images of the thyroid. Ultrasound may be better at detecting thyroid nodules than other tests, and there’s no radiation exposure.
Treatments
Hyperthyroidism Treatments
Several treatment options are available to those who are suffering from hyperthyroidism. Your age, the cause of hyperthyroidism, other medical conditions, and the severity of your symptoms will guide your doctor in creating a treatment plan specifically for you. For example, your doctor may order antithyroid medications and radioactive iodine to slow thyroid hormone production. Other treatments may include beta-blockers or surgery to remove all or part of your thyroid. Although hyperthyroidism is a severe condition if left untreated, most people respond well once treatment begins.
Beta-Blockers
are a class of drugs your doctor may prescribe to address specific symptoms such as tremors, nervousness, anxiety, rapid heart rate, and heart palpitations. You will feel better within hours or days, even though beta-blockers do not change the high levels of thyroid hormone in your blood.
Antithyroid Drugs
like methimazole (Tapazole®) or propylthiouracil (PTU) block the thyroid gland’s ability to make new thyroid hormones. Your doctor may choose this option to treat your hyperthyroidism. Many doctors prefer methimazole because it may have less severe side effects than other antithyroid drugs. Antithyroid drugs do not cause permanent damage to the thyroid gland. However, if you develop a fever, sore throat, severe fatigue, yellow eyes, or abdominal pain while taking these drugs, you should stop the medication immediately and contact your doctor.
Radioactive Iodine
treats hyperthyroidism by damaging or destroying the thyroid cells that make thyroid hormones. Your doctor may prescribe a one-time treatment of radioactive iodine to be administered through a small capsule taken by mouth. Your thyroid will absorb any iodine in your bloodstream, whether radioactive or not. This treatment can cause the thyroid or any thyroid nodules to shrink in size, and the level of thyroid hormone in the blood returns to normal. Any unabsorbed radioactive iodine leaves your body within days, weeks, or months. During this time, you may receive treatment with other medicines to control hyperthyroid symptoms.
Rarely, a patient will continue to experience hyperthyroidism, but to a lesser degree than before. In these unique situations, the doctor may order a second radioactive iodine treatment if needed. Hypothyroidism (underactive thyroid) occurs after a few months and lasts a lifetime. Creating an underactive thyroid is the goal because hypothyroidism is easily treated with thyroid hormone supplements. Radioactive iodine has been used to treat patients with hyperthyroidism for over 60 years and is generally safe with no apparent increase in cancer incidence in these patients.
Surgery
is a final option to cure hyperthyroidism permanently. During surgery, most or all of your thyroid gland is removed. Your doctor may prescribe certain medications before surgery to reduce the thyroid gland’s blood supply, simplifying the surgery and making it safer. After removing your thyroid gland, the source of your hyperthyroidism is gone, and you will become hypothyroid. Hypothyroidism (underactive thyroid) occurs after surgery and lasts a lifetime. The appropriate thyroid medications can restore your thyroid hormone levels to normal by taking a thyroid hormone supplement once a day.
Specialists
