Goiter

If you have a swelling in front of your neck at the lower side, you might be having a condition called goiter. Goiter is the enlargement of the thyroid gland, a small butterfly-shaped gland in the front part of the neck. This gland produces hormones that control many important body functions like metabolism, heart rate, physical growth, brain development, sexual development, etc.

There may be diffuse enlargement of the gland, or there might be a single or multiple small areas of growth called nodules. This enlargement may or may not be associated with the functional expression of the hormones. That is to say, There may be increased or decreased release of thyroid hormones or no change in the hormone levels at all. The increased levels (hyperthyroidism) are associated with increased heartbeat, diarrhea, anxiety, sweating, fatigue, etc. Whereas the lower levels (hypothyroidism) result in decreased heart rate, constipation, confusion, laziness, cold intolerance, etc., the goiter is treated according to the presentation of the disease. A very large goiter can also compress other vital structures in the neck like blood vessels, windpipe, food pipe, nerves, etc., necessitating its removal.

Goiter can be of the following types:

• Diffuse goiter: There is growth all over the gland equally. 
• Uninodular goiter: There is only one localized growth area called a nodule. 
• Multinodular goiter: There are many localized areas of growth. 

Goiter is a very common condition worldwide. It is prevalent in 15.7% of the world’s population, while it affects 4.7% of the people in the USA. Goiter affects more women than men. It is found less in older ages. 

The presence of the following risk factors can increase your chances of having goiter;

• Family history
• Iodine deficiency
• Sex- females are more affected than males
• Age – goiter incidence decrease as the age increases; however, the incidence of nodules increases with the increasing age.
• Other autoimmune disorders – like diabetes 1, rheumatoid arthritis, etc
• Pregnancy
• Medicines like amiodarone and lithium
• History of Radiation treatment of the neck

Following are the causes of goiter;

• Iodine deficiency: Iodine is needed for thyroid hormone production. Iodine deficiency is responsible for most cases of goiter worldwide.
• Hashimoto's thyroiditis: it is an autoimmune disorder. It is the most common cause of goiter in the USA. It causes hypothyroidism.
• Graves disease: it is also an autoimmune disorder that causes hyperthyroidism.
• Thyroid nodules: there may be single or multiple enlarged nodules in the thyroid gland whose cause is unknown. They may or may not release hormones.
• Thyroid cancer: Goiter can also occur as a result of thyroid cancer.
• Inflammation: Sometimes, an inflammation of the gland can also cause enlargement.
• Systemic diseases: The thyroid gland can be enlarged due to other systemic disorders like sarcoidosis, Amyloidosis, Cysts, Acromegaly, etc.

As discussed previously, the goiter may be asymptomatic or symptomatic. The symptoms depend on the amount of thyroid hormone, whether it is released more or less. A goiter that causes hormone disturbance is called a toxic goiter, While the one that doesn’t is called a non-toxic goiter. Due to enlarged size, symptoms can also be that of compression and obstruction of the structures in the neck region. 

Excessive thyroid hormone (hyperthyroidism)

• Increased basal metabolic rate, weight loss despite normal or increased appetite
• Heat sensitivity, warm moist skin, increased sweating
• Increased heart rate, palpitations
• Anxiety, irritability, depression, sleep disturbance
• Sexual dysfunction, changes in the menstrual cycle
• Diarrhea 
• Hyperactivity, Fatigue, tiredness
• Hair loss
• A fine tremor of hands

Decreased levels of thyroid hormone (hypothyroidism)

• Reduced basal metabolic rate
• Weight gain 
• Cold sensitivity, 
• Decreased heart rate, 
• Confusion, irritability, depression, sleep disturbance
• Sexual dysfunction, changes in the menstrual cycle
• Constipation 
• Fatigue, tiredness
• Hair loss

Compression symptoms

• Difficulty in breathing due to compression of the trachea
• Difficulty in swallowing due to compression of the esophagus
• Hoarseness of voice due to compression of a laryngeal nerve
• Cough due to compression of a laryngeal nerve 
• Snoring

A small goiter may not be evident or may not cause any symptoms. It may be incidentally found on imaging or physical examination of some other illness. Your doctor will ask questions about symptoms and examine you for the signs discussed above. You may be advised to have the following investigations;

• Blood tests: A blood sample would be taken to assess the levels of thyroid hormones (T3, T4 ) and thyroid-stimulating hormones(TSH). Thyroid antibodies may also be checked.
• Radioactive iodine uptake: Iodine is needed to make thyroid hormones. In this test, a small amount of radioactive iodine is given to the patient, and later a scan is done to check the activity of the thyroid gland
• Ultrasound: Ultrasound of the gland may be done
• Imaging tests: A CT scan or MRI can be done if the diagnosis is unclear.
• Biopsy: A piece of tissue is removed to get a clear histologic diagnosis.

Some other conditions can mimic the presentation of a goiter;

• Thyroglossal Duct Cyst
• Fibroma
• Thyroid Abscess
• Parathyroid Adenoma
• Lipomas
• Parathyroid Cyst

Treatment of goiter depends upon the presence or absence of symptoms, the amount and speed of growth, the presence of any cancerous tissue, and the patient’s preference for removal. Most of the time, goiter is asymptomatic and non-toxic. Such goiter does not need to be removed. For toxic goiters, the goal of treatment is to control the overproduction or underproduction of the hormones and to block their effects on the body.

For hyperthyroid goiters following treatment options are used;

• Radioactive iodine therapy: The patient is given radioactive iodine by mouth, which is taken up by the gland that destroys the overactive thyroid cells.
• Antithyroid medications: Propylthiouracil, methimazole: these medications interfere with the production of thyroid hormone by the gland at different levels and stop its production
• Beta-blockers: Propranolol, atenolol, etc. They do not stop the hormone production, but they block the effects of the hormone on the body and alleviate the symptoms of increased heart rate, anxiety, sweating, diarrhea, muscle weakness
• Surgery: Surgery can remove all or only some part of the gland.

For hypothyroid goiters following treatment options are used;

• Small doses of iodide are given if the goiter is caused by iodine deficiency, Lugol's iodine, or KI solution.
• For the cases of underproduction, supplemental thyroid hormone is given in the form of Levothyroxine sodium (Levoxyl, Synthroid, Levothroid)
• For pain and inflammation, NSAIDs are prescribed
• Surgery is done for goiters who may be obstructive, cancerous, or cosmetic purposes.

Most of the goiters are benign. However, a change in shape, texture, or growth must raise the alarm and be investigated for a possible cancerous transformation. 

Following habits should be adopted to decrease the chances of goiter;

• Care should be taken to include iodine-rich food in diet like dairy products, saltwater fish, etc
• People with a family history of thyroid disorders should be cautious about neck lumps.
• Should avoid too much consumption of goitrogens that are the foods that interfere with thyroid gland function, e.g., African cassava, broccoli, cabbage, Brussels sprouts.
• People with goiter should take their medicines properly and be vigilant for the follow-up visits.