Goiter is an enlargement of the thyroid gland. The  thyroid gland is a small  gland located in the neck,  below your Adam’s apple. The  thyroid can be enlarged due to generalized enlargement of the thyroid or nodules (tissue growths) within the thyroid.

The thyroid  gland produces the hormones thyroxine (also called T4) and a small amount  of triiodothyronine (also called T3). Most of  the T4 is converted  to T3 outside of  the thyroid. These thyroid hormones influence such bodily functions as a person’s body temperature, mood and excitability, pulse rate, digestive functions, and other processes necessary for life. It is important to understand that  goiter is not cancer and that most goiters are, in fact, benign. 

What causes goiter? 

Goiters have different causes depending on their type. Goiters  can be classified as simple, hereditary,  or due to other causes. Simple goiters  are further classified as endemic (colloid) or sporadic (nontoxic). 

Simple goiters are caused by an inadequate supply of thyroid hormone to meet the body’s need. The thyroid gland tries to make up for this deficiency by enlarging. 

Endemic goiters occur in people within certain geographic areas who do not get enough iodine in their diet (iodine is necessary to make thyroid hormone). The use of iodized table salt in the United States has limited the development of this type of goiter; however, iodine deficiency is still  common in parts of central Asia  and central Africa.

Sporadic goiters have no known cause. Sometimes certain types of drugs, such as lithium or aminoglutethimide, can cause this type of goiter. 

Hereditary factors also may cause goiters. Risk factors for goiter development include: 

• Female gender 
• Age over 40 
• Family history of goiter 

• Graves’ disease. Graves’ disease is an autoimmune disease (a disease in which your body’s immune system mistakenly attacks your healthy body). In this case, the thyroid gland is attacked, which  causes it to overstimulate and results in swelling of this gland. 
• Hashimoto’s disease. This is another autoimmune disease.  In this case,  the disease causes inflammation of  the thyroid gland, which in turn, results in underproduction of thyroid hormones. Attempts by other hormones to stimulate the thyroid gland  cause it to enlarge. 
• Nodular goiter. In this condition, tissue growths occur on one or both side  of the thyroid gland, resulting in an enlargement. 
• Thyroid cancer. Cancer of the thyroid gland often enlarges the thyroid. Thyroid cancer can be found in thyroid nodules though less than 5 percent of nodules are cancerous. A  goiter without nodules is not  a concern for cancer. 
• Pregnancy. A hormone secreted during pregnancy (human chorionic gonadotropin) can cause an enlargement  of the thyroid gland. 
• Thyroiditis. Inflammation of the thyroid gland itself can result  in an enlargement of  the thyroid gland. This can follow a viral illness or pregnancy. 
• Exposure to radiation. 

• A swelling, ranging  in size from a small nodule to a massive lump, in the front of the neck just below  your Adam’s apple.
• A feeling of tightness in  the throat area. 
• Difficulty breathing (shortness of breath), coughing, wheezing (due to compression of the windpipe). 
• Difficulty swallowing (due to compression of the esophagus). 
• Hoarseness.  
• Neck vein distention. 
• Dizziness when the arms are raised above the head. 

• An increased resting pulse rate 
• Rapid heartbeat 
• Diarrhea, nausea, vomiting 
• Sweating without exercise or increased room temperature 
• Shaking  
• Agitation  

• Fatigue, constipation, dry skin 
• Weight gain 
• Menstrual irregularities 

(The above group  of symptoms are signs of hypothyroidism -- a condition in which  the thyroid is underactive. Some people with  goiter may also have hypothyroidism.) 

How  is goiter diagnosed? 

Several testing methods can be used to diagnose goiter, including: 

• Physical exam  – Your doctor may be able to determine enlargement  of the thyroid gland by feeling your neck area  for nodules and signs of tenderness. 
• Hormone test  – A blood test to determine thyroid hormone levels (these tell you if the thyroid is functioning properly) 
• Antibody test  – A blood test to look for the production of certain antibodies that are produced in some forms of goiter. 
• Ultrasound of the thyroid  –An imaging test of your thyroid gland that reveals the gland’s size and possible presence of nodules. 
• Thyroid scan  – Another imaging test that provides information on the size and function of the gland. This test involves the use of a small amount of radioactive material injected into a vein. 
• CT scan or MRI (magnetic resonance imaging) scan of the thyroid.  These imaging tests are used to evaluate the size and extent of the goiter. 

How is  goiter treated? 

Treatment options depend  on the size of the enlargement, your  symptoms, and the underlying cause. Treatments typically considered by your doctor include: 

No treatment/"watchful waiting" 

If the goiter is small and not bothering you, your doctor may decide that no treatment is necessary at this time, but will continue to watch your condition for changes. 

Medications 

Levothyroxine (Levothroid, Synthroid) is a thyroid hormone replacement therapy that can be prescribed if your doctor determines that the cause of your goiter is an underactive thyroid (a condition called hypothyroidism). Other medications can be prescribed if tests indicate your thyroid is overactive (hyperthyroidism). Aspirin or a corticosteroid mediation might be prescribed if the underlying cause of your goiter is inflammation. Small doses of iodine (in the form of Lugol’s or potassium iodine solution) can be prescribed if the goiter is due to iodine deficiency. 

Radioactive iodine treatment 

This treatment, used in cases of an overactive thyroid gland, involves injecting radioactive iodine into your bloodstream. The iodine is delivered to the thyroid gland, killing thyroid cells, which shrinks the gland. Radioactive iodine treatment is usually followed by the use of hormone replacement therapy for life. 

Biopsy 

This may be required if you have large nodules in the thyroid to exclude cancer. 

Surgery 

Surgery, to remove all or part of the thyroid gland, may be necessary if the goiter is large and causing difficulty with breathing and swallowing or sometimes to remove nodules and certainly if cancer is present. Depending on the amount of thyroid gland removed, lifelong thyroid hormone replacement therapy may be necessary.