A goiter is an enlarged thyroid gland that causes the neck to swell.
A goiter is one of the most common thyroid disorders. It does not necessarily mean that the thyroid is functioning incorrectly. In some cases, however, it can signal an underlying thyroid disease that needs treatment.
Goiters are often harmless and may go away after a short time without treatment. People usually do not need treatment unless the goiter is large and causes bothersome symptoms.
Doctors can diagnose a goiter through a physical exam. They may also request blood tests or scans to find out the cause of the goiter.
This article provides an overview of goiters, including their symptoms, causes, treatments, and types.
A goiter is an enlarged thyroid gland.
The thyroid is a butterfly shaped gland situated in front of the windpipe. It is responsible for producing and secreting hormones that regulate growth and metabolism.
Most cases of a goiter are categorized as “simple” goiters. These do not involve inflammation or any detriment to thyroid function, produce no symptoms, and often have no obvious cause.
Some people experience a small amount of swelling. Others can have considerable swelling that constricts the trachea and causes breathing problems.
An enlarged thyroid does not necessarily mean that the thyroid gland is working incorrectly. A person with a goiter may have a thyroid gland that is:
- creating too much hormone, known as hyperthyroidism
- creating too little hormone, known as hypothyroidism
- creating the typical amount of hormone, known as euthyroidism
Goiters are more common in females than males, especially after menopause. Goiters and thyroid disease are generally more common after the age of 40.
In most cases, the only symptom of a goiter is a swelling in the neck. The swelling may be large enough to feel with the hand.
The degree of swelling and the severity of symptoms produced by the goiter depend on the individual.
When other symptoms occur, the following are most common:
- throat tightness, cough, and hoarseness
- trouble swallowing
- in severe cases, difficulty breathing
Other symptoms may be present because of the underlying cause of the goiter.
Hyperthyroidism, or an overactive thyroid, can cause symptoms such as:
- increased sweating
- heat hypersensitivity
- increased appetite
- hair loss
- weight loss
Hypothyroidism, or an underactive thyroid, can cause symptoms such as:
- an intolerance to the cold
- personality changes
- hair loss
- weight gain
There are a range of possible causes of a goiter, including:
The most common cause of goiters outside the United States is a lack of iodine in the diet. The thyroid needs iodine to create thyroid hormones, which regulate metabolism. A lack of iodine is uncommon in the U.S., as manufacturers add iodine to salt and other foods.
As iodine is less commonly found in plants, vegan diets may lack sufficient iodine. This is less of a problem for vegans who live in countries where manufacturers add iodine to salt.
Dietary iodine is found in:
- plant foods grown in iodine-rich soil
- cow’s milk
In some parts of the world, the prevalence of goiters can be as high as 80%. This includes remote mountainous areas of Southeast Asia, Latin America, and central Africa.
Hypothyroidism is the result of an underactive thyroid gland. When the gland produces too little thyroid hormone, it is stimulated to produce more, leading to swelling.
This usually results from Hashimoto’s thyroiditis, a condition in which the body’s immune system attacks its own tissue and causes inflammation of the thyroid gland.
Hyperthyroidism, or an overactive thyroid gland, is another cause of goiters. In people with this condition, the thyroid produces too much thyroid hormone.
This usually happens as a result of Graves’ disease, an autoimmune disorder where the body’s immunity turns on itself and attacks the thyroid gland, causing it to swell.
Less common causes of goiters include the following:
- Smoking: Thiocyanate in tobacco smoke interferes with iodine absorption and can cause enlargement of the thyroid gland.
- Hormonal changes: Pregnancy, puberty, and menopause can affect thyroid function.
- Thyroiditis: Inflammation caused by infection, for example, can lead to goiter.
- Lithium: This psychiatric drug can interfere with thyroid function.
- Too much iodine: This can trigger a swollen thyroid.
- Radiation therapy: This also can trigger a swollen thyroid, particularly when administered to the neck.
- Thyroid cancer: This is more common in females.
People over the age of 40 are at greater risk of goiters, as are people with a family history of the condition.
The type of goiter will dictate how it is treated and the possible symptoms. There are several main types of goiters:
- Multinodular goiter: In this common condition, multiple nodules develop in the thyroid.
- Diffuse smooth goiter: This occurs when the entire thyroid swells. These goiters are associated with overactive and underactive thyroid glands.
- Retrosternal goiter: This type of goiter can grow behind the breastbone. This can constrict the windpipe, neck veins, or esophagus, and sometimes requires surgery.
Most simple goiters are preventable through adequate intake of iodine, which is added to table salt in many countries. A range of iodine supplements are also available in health stores.
Medical professionals reserve active treatment of goiters for cases that cause symptoms. If the goiter is small and thyroid function is normal, people do not typically need treatment.
In cases caused by an underactive thyroid, or hypothyroidism, treatment is a synthetic replacement of thyroid hormone.
A doctor will gradually increase the dosage of synthetic thyroxine (T4) until their measurements indicate that the person’s normal thyroid function has been restored.
In goiters caused by an overactive thyroid, or hyperthyroidism, treatment aims to counter the excess hormone production.
For instance, antithyroid drugs, such as thionamide drugs, gradually reduce excessive hormone levels.
Another option is radioactive iodine to decrease thyroid function and stop hormone production.
Doctors will reserve surgery to reduce the size of the swelling for cases where the goiter is causing troublesome symptoms, such as difficulty breathing or swallowing.
Surgeons will usually perform thyroidectomies, the removal of part or all of the thyroid gland, when the person is under general anesthetic.
A healthcare professional may diagnose a goiter through a physical examination of the neck, palpating for swelling. They may ask the person to swallow while feeling for a goiter.
If they suspect a goiter, they may recommend further tests to determine any underlying problems with thyroid function, such as hyperthyroidism or hypothyroidism.
Thyroid function tests are blood tests that measure levels of thyroid-stimulating hormone (TSH) and thyroxine. A carefully controlled feedback mechanism means that TSH stimulates the thyroid to produce more thyroxine, while T4 tells the thyroid to stop producing as much thyroxine.
With an overactive thyroid, TSH levels are low or non-existent, and T4 levels are high. In people with underactive thyroid, the reverse is true. TSH levels are high and T4 levels are low.
In some cases, such as suspected Graves’ disease, healthcare professionals may test for another hormone, triiodothyronine.
They may also recommend special tests, such as:
- Radioactive iodine scan: This provides a detailed picture of the gland following an injection of radioactive iodine.
- Ultrasound scan: This assesses the gland and the size of the goiter.
- Fine-needle aspiration: A doctor may perform a biopsy to remove a sample of cells from within the gland if, for example, they suspect cancer.
A goiter is a swelling of the thyroid gland. It is often harmless, though it can signal an underlying thyroid condition.
Depending on its cause, a goiter may go away without treatment. Doctors may recommend treatments if there is an underlying thyroid disease, or if the goiter gets in the way of a person’s daily life.