Goiter: Summary and Overview
Goiter is the swelling of the thyroid gland. Your thyroid is a butterfly-shaped gland at the base of the neck. The thyroid gland produces the hormone thyroxine (also called T4) and a small amount of triiodothyronine (also called T3). Outside the thyroid, most of the T4 is converted to T3. These thyroid hormones influence such bodily functions as a person’s body temperature, mood and excitability, digestive functions, pulse rate, and other processes necessary for life.
Goiters are generally painless, although they can press on your airways, causing you to cough, or make it difficult for you to swallow or breathe. The most common cause of goiters is a lack of iodine in the diet. Although goiter used to be common problem in the United States, the introduction of iodized salt in 1924 has meant that the disease is now fairly rare in the western world, although it still occurs in countries where access to iodine is limited.
The most common type of goiter is caused by an iodine deficiency. It is called simple goiter, endemic goiter, colloid goiter or iodine-deficient goiter. Lots of names for essentially the same condition!
Goiter used to be common in the United States in the Great Lakes, Midwest, and inner mountain areas of the United States. This was the area once called the “goiter belt” because of its high incidence of the condition. These areas had iodine-poor soil, away from the coast. In early 1923, Dr. David Murray Cowie of the University of Michigan contacted American salt producers to ask them to iodinize their salt. It took a year of negotiations, but in 1924, iodized salt was commonly available in the U.S., and goiter rates began to drop greatly.
By contrast, sporadic goiters usually have no known cause. Sometimes certain types of drugs, such as lithium or aminoglutethimide, can cause this type of goiter. Some diseases can cause it too.
Hereditary factors also may cause goiters.
Risk factors for goiter development include:
- Graves’ disease. Graves’ disease is an autoimmune disease, where your immune system attacks your healthy body. In this case, the immune system attacks the thyroid gland, which causes it to over-stimulate and results in swelling of this gland.
- Hashimoto’s disease. This is also an autoimmune disease. The immune system attacks the thyroid, which causes the underproduction of thyroid hormones. This type of goiter usually resolves on its own over time.
- Thyroid cancer. Cancer of the thyroid gland often enlarges the thyroid.
- Pregnancy. A hormone secreted during pregnancy can cause an enlargement of the thyroid gland.
- Thyroiditis. Sometimes a viral illness or a pregnancy can cause inflammation of the thyroid gland. However this condition tends to go away with time.
- Nodular goiter. In this condition, tissue growths occur on one or both side of the thyroid gland, resulting in an enlargement.
- Exposure to radiation: Radiation treatment can damage the thyroid.
Goiter: Signs and Symptom
Goiters usually appear as swelling or mass in the middle of the neck. As the goiter expands, it can cause compression of your airways (trachea), or compression of the esophagus.
- Swelling at the base of the neck.
- A tightness in the your throat.
- Fast, shallow breathing.
- Difficulty swallowing or breathing.
- Dizziness when the arms are raised above the head.
- An increased resting pulse rate, palpitations, or high blood pressure.
- Rapid heartbeat.
- Diarrhea, nausea, vomiting.
- Sweating and shaking.
- Restlessness, nervousness, irritability, and anxiety.
Goiter: Diagnostic Tests
Often a goiter will be diagnosed simply through a routine physical exam. Your doctor will feel your neck and have you swallow a few times. Sometimes, your doctor may be able to feel the presence of tissue growths or nodules. In some cases, diagnosis may require one or more of the following tests:
- A hormone test. Blood tests can determine the amount of hormones produced by your thyroid and pituitary glands. If your thyroid is underactive, the level of thyroid hormone will be low. If overactive, there will be a high level of thyroid hormone.
- An antibody test. Some causes of goiter involve production of abnormal antibodies. A blood test may confirm the presence of these antibodies.
- Ultrasound of the thyroid – An imaging test of your thyroid gland reveals the gland’s size and possible presence of nodules.
- Thyroid scan –This test involves the use of a small amount of radioactive material injected into a vein. By imaging the radioactive dye as it travels through the thyroid, it provides information on the size and function of the gland.
- 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.
- A biopsy. During a fine-needle aspiration biopsy, a tissue sample is extracted from the thyroid with a fine-needle.
Goiter: Treatment Options
Treatment of goiters depends on what’s causing the condition and how advanced it is.
Your doctor will probably recommend one of the following:
- Wait and See: If your goiter is small and is more an annoying inconvenience than a condition that seriously impacts your health, your doctor may suggest a wait and see approach. Sometimes goiters heal themselves.
- Medications. The drugs used to treat goiter will depend on whether you have hypothyroidism (underactive gland) or hyperthyroidism (overactive thyroid). For hypothyroidism, levothyroxine sodium (Levoxyl, Synthroid)] is the preferred treatment. For hyperthyroidism, the treatment often takes the form of treating the symptoms of the disease and some antithyroid hormone producing medication.
- Surgery. Removing all or part of your thyroid gland is an option if you have a large goiter that is causing difficulty breathing or swallowing, or in some cases, if you have nodular goiter causing hyperthyroidism, and certainly if you have thyroid cancer.
- 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. The treatment may reduce the size of the thyroid, but it may also lead to an underactive thyroid glad. Hormone replacement therapy with a synthetic thyroid hormone becomes necessary usually for the rest of your life.
To help prevent goiter, it’s necessary to make sure that you get enough iodine in your diet. Use iodized salt or eat seafood or seaweed about twice per week. Shellfish such as shrimp are particularly good sources. Although rare, too much iodine can also cause thyroid problems, in which case, cut back on sources such as shellfish and iodized salt.
Goiters were once a common problem in the United States. But since the introduction of iodized salt in 1924, this health condition, which is usually caused by an iodine deficiency, has decreased greatly. Today, goiters still occur, although they are rare. They may be sporadic (no known cause), hereditary, caused by a disease or condition or something else. Goiters may heal themselves, and for this reason, if they are small and not causing major health problems, they may be left alone, under careful observation by a medical practitioner.