Hyperthyroidism occurs when your body produces too much thyroid hormone. The most common conditions that lead to hyperthyroidism are Graves’ disease, Plummer’s disease, and toxic adenoma.

Your thyroid is a gland in your neck. The hormones that this gland produces control important body functions such as metabolism and temperature.

When your thyroid gland makes too much thyroid hormone, it can enlarge, creating a visible bump in the neck called a goiter. Hyperthyroidism can also affect your heart, digestive system, energy levels, mood, and more.

Many conditions can lead to hyperthyroidism, but it’s most commonly caused by the three reviewed in this article:

  • Graves’ disease
  • Plummer’s disease
  • toxic adenoma

Graves’ disease is an autoimmune disease that causes your immune system to attack your thyroid gland. Repeated immune attacks on your thyroid gland lead to your thyroid gland overproducing thyroid hormone.

Graves’ disease is the most common cause of hyperthyroidism.

Symptoms

Symptoms of Graves’ disease vary from person to person. They can also come and go over time. Common symptoms include:

Risk factors

The exact cause of Graves’ disease is unknown. It’s likely that a combination of genetic and environmental factors leads to the condition. However, there are some known risk factors that make developing Graves’ disease more likely. These include:

Plummer’s disease is also called toxic multinodular goiter. This condition is the second most common cause of hyperthyroidism.

People with Plummer’s disease have two or more thyroid nodules that overproduce thyroid hormone.

Symptoms

Many of the symptoms of Plummer’s disease overlap with the symptoms of Graves’ disease.

Plummer’s disease can cause all of the non-eye and skin symptoms associated with Graves’ disease. These symptoms are caused by the overproduction of thyroid hormone and include:

  • a goiter
  • weight loss
  • insomnia
  • fatigue
  • sweating
  • rapid heart rate
  • irregular menstrual cycles
  • muscle cramping
  • restlessness
  • mood changes

Risk factors

Researchers believe that there is a genetic component to Plummer’s disease. It seems to run in families, and having a family member with the condition is a significant risk factor. Additional risk factors include:

  • being assigned female at birth
  • smoking
  • being over 55

A thyroid adenoma is a noncancerous lesion on your thyroid. Some thyroid adenomas are inactive because they don’t produce thyroid hormones. Other thyroid adenomas are active and do produce thyroid hormones.

It’s rare for a thyroid adenoma to cause a large enough overproduction of thyroid hormone to lead to hyperthyroidism. When it does, it’s called toxic adenoma.

Symptoms

When adenomas are toxic, they can cause the same symptoms as other types of hyperthyroidism.

Sometimes, the thyroid adenomas can push on structures in the throat, such as the larynx and trachea, and lead to additional symptoms. These can include:

Risk factors

The exact cause of toxic adenoma isn’t known, but thyroid adenomas tend to run in families. Having a family member with a thyroid adenoma increases your risk of toxic adenoma.

Additional risk factors include:

  • being assigned female at birth
  • having low levels of iodine in your body
  • being older than 60

A medical appointment is the first step in getting a hyperthyroidism diagnosis. A doctor will discuss your symptoms along with your medical history and your family’s medical history.

If your doctor suspects you have hyperthyroidism, they’ll order tests to confirm the diagnosis. This might include:

  • Blood work: Blood tests can look for levels of thyroid hormones in the body.
  • Imaging scans: Imaging tests such as ultrasounds and CT scans can get an up-close at your thyroid gland to look for swelling, growths, and other changes.

The exact treatment plan for your hyperthyroidism will depend on:

  • the underlying cause
  • your symptoms
  • the severity of your condition.

The goal of treatment is to manage your symptoms and to bring your thyroid hormone levels back to a normal range.

Hyperthyroidism treatments include:

  • Medications: Antithyroid medications can slow down and block the production of thyroid hormone to help control your thyroid hormone levels.
  • Radioactive Iodine ablation: This treatment uses radioactive iodine to slowly and safely damage your thyroid. This treatment is done by swallowing a capsule or liquid that contains radioactive iodine that your thyroid then absorbs. After this treatment, you’ll likely need to take a controlled dose of thyroid hormones to replace what your damaged thyroid gland is no longer able to make.
  • Surgery: Sometimes, surgery to remove the thyroid gland is the best treatment choice. Typically, this treatment is used when other treatments haven’t worked. Similar to radioactive iodine ablation, you’ll need to take replacement thyroid hormones after you have thyroid removal surgery.

Hyperthyroidism is a condition that occurs when the thyroid gland overproduces thyroid hormone.

Thyroid hormone is vital to several body functions, and overproduction of thyroid hormone leads to a range of symptoms, including weight loss, a rapid heart rate, and fatigue.

There are multiple conditions that can lead to hyperthyroidism. The most common ones are:

  • Graves’ disease: an autoimmune condition that can also cause eye-related symptoms
  • Plummer’s disease: a condition that causes thyroid nodules to overproduce thyroid hormone
  • Toxic adenoma: a growth on the thyroid that can produce excess thyroid hormones

The exact treatment for hyperthyroidism depends on the cause and the symptoms but can include medications, radioactive iodine ablation, and surgery.