A goitre (sometimes spelt "goiter") is an abnormal swelling of the thyroid gland that causes a lump to form in the throat.
The thyroid gland is a small butterfly-shaped gland in the neck, just in front of the windpipe (trachea). It produces thyroid hormones, which help to regulate the body's metabolism (the process that turns food into energy).
The thyroid gland is not usually noticeable. However, if it swells it produces a lump in the throat known as a goitre.
The size of a goitre can vary from person to person. In most cases, the swelling is small and does not cause any symptoms. However, in more severe cases, the swelling can increase so dramatically that breathing and swallowing are affected.
Learn more in symptoms of goitre.
What causes a goitre?
Goitres can have several possible causes including:
- an overactive thyroid gland (hyperthyroidism)
- an underactive thyroid gland (hypothyroidism)
- a lack of iodine (a trace mineral found in milk and fish) in the diet
Learn more in causes of goitre.
Treating a goitre
The treatment for goitres depends on the underlying cause. If the goitre is small and not causing any problems, a wait-and-see approach is usually recommended.
Other possible treatments include thyroid hormone replacement, dietary supplements and, in the most severe cases, surgery. Although most goitres are usually benign (non-cancerous) it is estimated that in 1 in 20 cases they may be a sign of thyroid cancer.
Learn more in treatment of goitre.
Who is affected
Goitres are a common condition, affecting an estimated 4% to 7% of people. However, in most cases, the swelling is so small it can't be seen. Goitres are more common in women than men.
The main symptom of a goitre is swelling of the thyroid gland (a gland in the neck that produces hormones), which causes a lump to develop in the throat.
The lump will move up and down when you swallow.
Types of goitre
There are two different types of goitre:
- diffuse small goitre, where your entire thyroid gland swells to a larger size and feels smooth to the touch
- nodular goitre, where certain sections, or "nodules", of your thyroid gland swell and feel lumpy to the touch
Other associated symptoms can include:
- a tight feeling in your throat
- changes to your voice, such as hoarseness
- less commonly, difficulty swallowing (dysphagia) or difficulty breathing, such as a high-pitched sound when you breathe (stridor)
There are several causes of goitre, which is a swollen thyroid gland. Sometimes no definite cause can be found.
Iodine deficiency used to be the major cause of goitres, but it is now rare in Europe due to changes in our diet. It remains a significant problem in parts of the developing world.
Iodine is a trace element found in seawater and soil. It enters the food chain through plants that grow in iodine-rich soil, or through fish or plants from the sea. Iodine is found in:
- seafood, such as fish, shellfish or seaweed
- plant foods, such as cereals or grains
- cow’s milk
The thyroid gland (a gland in the neck that produces hormones) needs iodine to help manufacture thyroid hormones (chemicals released into the bloodstream that control the body's growth and metabolism). If your body does not receive enough iodine, your thyroid gland becomes underactive, and will expand in order to produce more thyroid hormones.
In the UK, iodine deficiency used to be a common problem until the early 1900s, when salt manufactures started to add small amounts of iodine to salt, which reduced the number of cases.
However, in recent years, the number of people experiencing iodine deficiency in the UK has started to rise. This could be due to an increased number of people preferring a low-salt, non-dairy diet. Iodine deficiency can be a problem for people following a strict vegan diet.
Overactive thyroid gland
A goitre can develop if the thyroid gland becomes overactive (hyperthyroidism), leading to too many thyroid hormones being produced. Increased hormone production over-stimulates the thyroid gland and causes it to swell.
The leading cause of hyperthyroidism is a condition called Graves' disease. Graves' disease causes your immune system (the body’s natural defence system) to send antibodies (proteins that fight infections) to your thyroid gland. The antibodies stimulate the thyroid gland, causing an increased amount of thyroid hormones to be released.
See hyperthyroidism for more information about this condition.
Underactive thyroid gland
A goitre can also develop if the thyroid gland becomes underactive (hypothyroidism). If the thyroid gland does not produce enough thyroid hormones, the body will stimulate it to produce more. This can cause the thyroid gland to swell.
As well as iodine deficiency, one of the leading causes of hypothyroidism is a condition called Hashimoto's thyroiditis, sometimes known as Hashimoto's disease.
As with Graves' disease, Hashimoto's thyroiditis is an autoimmune disease. Rather than over-stimulating the gland, Hashimoto's thyroiditis interferes with the gland's ability to produce hormones. In order to compensate for this, the body causes the gland to swell, resulting in a goitre.
Read more about Hashimoto's thyroiditis.
There may also be a link between smoking and an increased risk of developing a goitre. This may be because tobacco smoke contains a chemical called thiocyanate, which can interfere with the body's ability to make use of iodine.
Smokers who have a low-iodine diet are particularly at risk. See quitting smoking for help to stop smoking.
A number of other causes have been linked to goitres. These are outlined below.
Pregnancy and puberty
The changes in hormone levels that occur during pregnancy and puberty (when a child gradually progresses to a sexually developed adult) can affect the thyroid gland.
Lithium is a medicine often used to treat a number of mental health conditions, such as depression and bipolar disorder (a condition that affects your moods, which can swing from one extreme to another). Lithium can interfere with how your thyroid gland functions.
A number of bacteria, parasites and fungi that cause infections are also known to cause goitres.
An excessive amount of iodine can build up in the body as a result of eating too much iodine-rich food. For example seaweed, particularly kelp (a type of brown seaweed that contains many different minerals), is a rich source of iodine. An excess amount of iodine can affect the thyroid gland.
Exposure to radiation
Exposure to radiation (energy waves that travel through the air) can sometimes cause goitres. Radiation is used to treat some health conditions (radiotherapy), such as cancer. Receiving radiotherapy to the neck can sometimes cause goitres.
Non-cancerous growths can also sometimes cause goitres.
Thyroid cancer is another possible cause of goitres, although it is rare in the UK. Cancer Research UK estimates that six out of every 1,000 cancers diagnosed in the UK are thyroid cancer.
See thyroid cancer for more information about this condition.
An antibody is a protein that is produced by the body to neutralise or destroy disease-carrying organisms and toxins.
Hormones are groups of powerful chemicals that are produced by the body and have a wide range of effects.
The immune system is the body's defence system, which helps protect it from disease, bacteria and viruses.
The thyroid gland is found in the neck. It produces hormones that are released into the bloodstream to control the body's growth and metabolism (the process that turns food into energy).
If you suspect you have a goitre, see your doctor. Your doctor will carry out a series of tests that can help diagnose goitre.
They will carry out a physical examination of your neck, to see if there is evidence of swelling of the thyroid gland. They may also test your thyroid gland to see how well it is working.
Your doctor will examine your neck to assess the size and extent of any swelling, and determine whether it is:
- a diffuse small goitre, where your entire thyroid gland swells up
- a nodular goitre, where certain sections, or "nodules", of your thyroid gland swell up
They may also ask you to swallow to see whether the lump then moves up and down.
Your doctor may arrange for a thyroid function test in order to discover the underlying cause of your goitre.
Thyroid function test
A thyroid function test measures the level of certain hormones (chemicals produced by the body) in your blood. This test can help to show whether you have an underactive or overactive thyroid, both of which are associated with goitre.
The thyroid gland produces two hormones:
An excessive amount of these two hormones would indicate an underlying condition that is making your thyroid gland overactive, such as Graves' disease (an autoimmune condition that causes your body to attack itself).
If your thyroid gland is underactive, your pituitary gland (a pea-sized gland that sits below the brain) will produce a hormone called thyroid stimulating hormone (TSH).
TSH is released by your body in order to stimulate your thyroid gland. A high level of TSH in your blood would indicate that your thyroid gland is underactive.
If you are referred to a specialist, you may have further tests in hospital. These are described in more detail below.
Radioactive iodine scan
During a radioactive iodine scan, a small amount of radioactive iodine is injected into your vein. The iodine then builds up in your thyroid gland and can be studied using a special camera.
The scan can provide more information about the structure and function of your thyroid gland. The amount of radiation used is perfectly safe for most people, although may not be suitable if you are pregnant.
An ultrasound scan uses high-frequency sound waves to create an image of part of the inside of your body. It can be used to:
- build up a picture of the inside of your thyroid gland
- assess the size of your thyroid gland
- check if there are any enlarged nodules in your thyroid gland not found during the physical examination
Fine needle aspiration
Fine needle aspiration is a procedure used to extract a sample of the goitre to test the cells inside it. This procedure can be called a biopsy.
During the procedure, a fine needle on the end of a syringe will be inserted into the goitre in your throat. A sample of the fluid or tissue inside the goitre will be sucked through the needle and into the syringe. The sample will be examined under a microscope to determine what kind of cells are inside the goitre.
Treatment for goitre can include medication and surgery. The treatment you receive will depend on:
- the size of the goitre
- the symptoms the goitre is causing
- whether you have any underlying health conditions, such as an overactive or underactive thyroid gland (a gland in your neck that produces hormones)
If tests reveal your thyroid gland is working normally, and the goitre is small, no immediate treatment may be recommended. Your condition may just be monitored.
If you have a problem with your thyroid gland, it will be treated. If this does not improve your condition, you may need surgery. One study estimated that up to one-in-seven people with goitres may eventually require surgery.
Underactive thyroid gland
If testing reveals an underactive thyroid gland, one treatment involves using a synthetic (man-made) hormone to replicate your normal thyroid function. This is called hormone therapy.
The synthetic hormone, which is called levothyroxine, is taken orally (by mouth), usually once a day.
Side effects of levothyroxine can include:
- an irregular or rapid heartbeat
- muscle cramps (when your muscles suddenly shorten, causing pain)
- weight loss
- problems sleeping
These side effects should pass in a few days as your body gets used to the hormone. However, if they continue you should speak to your doctor because your dosage may need to be adjusted. In most cases, hormone therapy will need to be maintained for the rest of your life.
See treatment for hypothyroidism for more information.
Overactive thyroid gland
If you have an overactive thyroid gland, there are several recommended treatments. Some are described below.
Thionamides are drugs that help to reduce the amount of thyroid hormones your thyroid gland is producing.
Thionamides are usually taken orally (by mouth). The medicine works by gradually reducing levels of thyroid hormones, so it may be several weeks before you notice any effects.
Side effects of thionamides include:
- a mild skin rash
- pain in your joints
- nausea (feeling sick)
- itchy skin
In very rare cases, thionamides can cause a serious condition called agranulocytosis (a sudden drop in the number of white blood cells). If this occurs, it will usually be during the first three months of treatment. Signs to look out for include:
- a high temperature (a fever) of 38C (100.4F) or above
- sore throat
- mouth ulcers
See your doctor if you notice any of the above.
You may need to take thionamides for two-to-four months before your thyroid gland is under control.
Radioactive iodine is another treatment for an overactive thyroid gland that is taken orally (by mouth). When the iodine reaches your thyroid gland, it destroys the thyroid cells and reduces the size of the goitre. However, the treatment may cause your thyroid gland to become underactive. If this happens, you may need hormone therapy (see above).
See treatment for hyperthyroidism for more information.
Your doctor may recommend iodine supplements if your goitre is caused by an iodine deficiency.
Iodine supplements are also available in many health food shops without prescription. However, always consult your doctor before taking them because the amount of iodine needed varies from person to person. Taking too much iodine may cause other health problems and it could also have toxic (poisonous) effects.
If your goitre is interfering with your breathing, or swallowing, and has not responded to other forms of treatment, surgery may be required to remove part, or all, of your thyroid gland.
You will be given a general anaesthetic, so you will be unconscious and unable to feel anything.
During surgery, the surgeon will make an incision (cut) in the front of your neck so they can see your thyroid gland. They will usually remove half of it. This should reduce the amount of thyroid hormones being produced and the size of your goitre.
The surgeon will attempt to remove enough of your thyroid gland to relieve your symptoms, while leaving enough so that normal thyroid hormone production can continue. However, you may require hormone therapy following surgery if this isn't possible.
Surgery to remove the thyroid gland is usually safe, but as with all surgical procedures there is a risk of complications, such as post-operative infection. other possible complications are briefly described below.
The thyroid gland is very close to the two laryngeal nerves (the nerves that control your vocal cords). If these are accidentally damaged during surgery, your voice and breathing could be affected.
Permanent damage to the laryngeal nerves affects one or two people in every 100 who have this type of surgery. Temporary damage may affect up to five people in every 100.
Parathyroid gland damage
The parathyroid glands are glands that help to regulate the amount of calcium (a mineral that is needed for strong teeth and bones) in your body. If the parathyroid glands are damaged, you will probably need to take calcium supplements for the rest of your life.
The risks of complications occurring after thyroid gland surgery are estimated to be 1% to 2%.