Autoimmune Thyroid Diseases
What are autoimmune thyroid diseases?
Autoimmune thyroid diseases, such as autoimmune thyroiditis, which is also known as Hashimoto’s thyroiditis or chronic lymphocytic thyroiditis, are conditions in which the immune system attacks the body’s own thyroid gland. The thyroid gland, which is a small gland at the front of the neck, becomes chronically inflamed and decreases production of the thyroid hormones triiodothyronine and thyroxine. Because these hormones are used almost everywhere in the body, autoimmune thyroid diseases can have widespread, serious effects and many symptoms.
Autoimmune thyroid diseases are generally hereditary in origin, although environmental factors, such as infection, certain drugs, and iodine consumption, can play a role in their progression. Autoimmune thyroiditis is more common in women than in men, and it primarily affects people between 40 and 60 years of age. Like many autoimmune disorders, your chances of getting autoimmune thyroiditis are increased if you have other autoimmune disorders.
Often, mild autoimmune thyroiditis can be symptomless. In more serious cases, however, inflammation of the thyroid can lead to enlargement (goiter). Over time, the thyroid can suffer more damage, leading to symptoms of hypothyroidism (underactive thyroid), such as fatigue, weight gain, body aches, depression, and lethargy.
Autoimmune thyroiditis may not always require treatment. For those who do experience problematic symptoms, treatment is generally in the form of synthetic thyroid hormones. Generally, the disease is slow to progress and can remain stable for many years without complications.
While chronic autoimmune thyroid diseases are generally mild or even symptomless, they can progress to significant hypothyroidism. Seek prompt medical care for worrisome symptoms of hypothyroidism, such as depression or unexplained weight gain.
What are the symptoms of autoimmune thyroid diseases?
In many cases, autoimmune thyroid diseases may be symptomless. Symptoms of chronic autoimmune thyroiditis are related to low levels of thyroid hormones, which can slow metabolism and affect many body systems.
Common symptoms of autoimmune thyroid diseases
You may experience autoimmune thyroid diseases symptoms daily or just once in a while, if at all. At times, any of these symptoms may be severe:
- Dry skin
- Goiter (enlargement of the thyroid gland)
- Hair loss
- Joint stiffness
- Missed menstrual periods
- Unexplained weight gain
Symptoms that might indicate a serious condition
In some cases, autoimmune thyroid diseases can be serious and should be evaluated in an emergency setting. Seek immediate medical care (call 911) if you, or someone you are with, have any of these serious symptoms including:
What causes autoimmune thyroid diseases?
Autoimmune thyroid diseases arise when the body attacks its own thyroid gland. When the immune system develops antibodies to thyroid tissue, it treats the thyroid gland as an invader of the body. This causes inflammation of the thyroid gland, which can destroy thyroid tissue over time. The thyroid is responsible for creating two hormones, triiodothyronine and thyroxine. Low levels of these hormones can lead to the symptoms of autoimmune thyroid disease.
In rare cases, autoimmune thyroiditis can occur as part of an autoimmune disorder that affects multiple endocrine glands. Such autoimmune disorders are known as polyglandular autoimmune syndrome I and II. In these conditions, other glands, such as the pancreas, adrenal glands, and parathyroid, may be targeted by the immune system.
Autoimmune thyroiditis is thought to be genetic in origin. Like many autoimmune disorders, it is more likely to occur with autoimmune disorders of other organ systems. Environmental factors such as infections, iodine overconsumption, or medication side effects may also play a role in the development of autoimmune thyroid diseases, although the extent to which such factors influence the disease is not known.
What are the risk factors for autoimmune thyroid diseases?
A number of factors increase the risk of developing autoimmune thyroid diseases. Not all people with risk factors will get autoimmune thyroid diseases. Risk factors for autoimmune thyroid disease include:
How are autoimmune thyroid diseases treated?
Often, autoimmune thyroid diseases can be symptomless or may not require medical treatment. In cases in which symptoms become bothersome, autoimmune thyroiditis may be treated with a synthetic thyroid hormone, such as levothyroxine (Levoxyl, Synthroid). In some cases, autoimmune thyroid disease symptoms, such as goiter, may resolve themselves over time.
What are the potential complications of autoimmune thyroid diseases?
Generally, autoimmune thyroid diseases themselves are mild and unlikely to lead to complications. In serious or untreated cases, however, bothersome complications can result. These complications are primarily related to decreased thyroid hormone production, and can include:
- Hypothyroidism (underactive thyroid)
- Unexplained weight gain