Hyperthyroidism

Overview

What is the thyroid?

The thyroid is a gland located at the bottom front of the neck, just below the Adam’s apple. It is shaped like a butterfly and produces important hormones that regulate metabolism and has an effect on all organs in the body. The two hormones that are produced by the thyroid gland are T3 and T4.

What is hyperthyroidism?

Hyperthyroidism happens when your thyroid gland is overactive and produces too much thyroxine, one of the two main hormones it produces. When this happens, your body’s metabolism can speed up, leading to effects like unintentional weight loss or a rapid heart rate. 

Is hyperthyroidism related to Grave’s disease or diabetes?

An autoimmune disease, such as Grave’s disease, can be one of the underlying causes of hyperthyroidism. An autoimmune disease is when a body produces antigens that attack its own cells. With Grave’s disease, the body produces antibodies that overstimulate the production of hormones by the thyroid. 

Thyroid diseases can also be related to diabetes since insulin and thyroid hormones interact. Hyperthyroidism can change hormone interactions in a diabetic patient so that insulin gets removed from the body quicker, meaning you would have to take a higher dose of insulin.

Can hyperthyroidism be cured?

Hyperthyroidism can be effectively treated, but it is tricky to cure without interfering with the thyroid gland itself. Treatment often restores thyroid function to normal and may require maintenance through consistent medication. 

What is the difference between hyperthyroidism and hypothyroidism?

Hyperthyroidism is an increase in the amount of hormones made by the thyroid, whereas hypothyroidism is a lack of sufficient hormones being made. With hyperthyroidism, people can have more energy, feel more anxious, and lose weight unintentionally. The symptoms of hypothyroidism are usually the opposite, with more tiredness, weight gain, and possible depressive moods. Hypothyroidism is more common than hyperthyroidism in the US.

Causes

What are the causes of hypothyroidism?

There are several reasons why a person can develop hyperthyroidism. Below are a few underlying reasons:

  • Grave’s Disease: The most common cause of hyperthyroidism is this autoimmune disorder in which antibodies produced by your immune system overstimulate the thyroid to produce too much T4. 
  • Hyperfunctioning Nodules (like in Plummer’s Disease): An adenoma is a part of a gland that has become a benign (noncancerous) lump in the thyroid. One or more adenomas can drastically increase the amount of T4 being produced by the thyroid. 
  • Thyroiditis: This is an inflamed thyroid that can occur for many reasons. Often, the thyroid can become inflamed after pregnancy, or it happens because of an autoimmune condition. The inflammation leads excess hormone from the thyroid to lead into the bloodstream.

What are the risk factors for hyperthyroidism?

  • Having a family history of autoimmune diseases, specifically Grave’s disease 
  • Being female, since women are likelier to have this condition than men
  • Personal chronic illnesses, such as Type 1 Diabetes 

Symptoms

What are the symptoms of hyperthyroidism?

Hyperthyroidism can have symptoms that mimic other health issues, making it difficult to diagnose and often requires a blood test for confirmation. Common symptoms of hyperthyroidism include the following:

  • Unintentional weight loss with no change in appetite or food intake
  • Rapid heartbeat, often over 100 beats per minute
  • Enlarged thyroid gland with swelling at the base of your neck
  • Increased sensitivity to heat and unusual sweating
  • Irregular heart beat
  • Heart palpitations 
  • Changes in menstrual patterns 
  • More frequent bowel movements
  • Graves’ ophthalmopathy: dry eyes, red or swollen eyes, excessive tearing, light sensitivity, blurred or double vision, protruding eyeballs.
    • Though uncommon, this is an issue that occurs, especially in smokers. These problems can often improve even without treatment. 

Diagnosis

How does hyperthyroidism get diagnosed?
Because hypothyroidism symptoms can look like many other health issues, it is important to have a screening or blood test done for a concrete diagnosis. A doctor may check to see if you have a tremor, overactive reflexes, or subtle changes in your vision or your skin. In addition to a physical exam, diagnosis may include imaging tests. If you suspect that you are at risk or have symptoms, talk with your doctor about getting screened. 

Treatment

How is hyperthyroidism treated?

Hyperthyroidism can often be harder to treat than hypothyroidism, with treatment options including antithyroid medications, surgery, or radioiodine therapy. 

  • Antithyroid medications (like methimazole): Can cause a reduction in hormone production by the thyroid. 
  • Surgery: If a patient elects to have surgery to remove all or part of the thyroid, treatment with synthetic hormones would be necessary. 
  • Radioiodine therapy: Means taking radioactive iodine via the mouth, which slowly kills some of the cells overproducing the thyroid hormones to normalize production levels. This therapy is widely used but may have to be used multiple times in order to be effective.

Information

Medically reviewed by:

Jodi B. Nagelberg, MD, MHA

Dr. Jodi Nagelberg is an endocrinologist, with board certification in Internal Medicine. She also holds a masters in Health Administration and Policy. She joins TeleMed2U as Endocrinology Director and supports our mission to increase access to healthcare for patients everywhere.

Postgraduate: University of Southern California Sol Price School of Public Policy Los Angeles, CA  Masters, Health Administration and Policy, 2011