Definition Hashimoto's thyroiditis is a chronic inflammation of the thyroid gland. The cause of the condition is not known. The thyroid gland is in the front of the neck just below the Adam's apple. It secretes thyroid hormone, which is important in metabolism throughout the body.
What is going on in the body? Hashimoto's thyroiditis is considered an autoimmune disease. This means that a person's immune system attacks his or her own body for unknown reasons. In Hashimoto's thyroiditis, the immune system attacks the thyroid gland. This can cause thyroid hormone imbalances. Hashimoto's is one of the most common causes of a low thyroid hormone level, or hypothyroidism.
What are the signs and symptoms of the disease? Symptoms of Hashimoto's thyroiditis may include:
These symptoms are primarily related to having a low thyroid hormone level. The low level often occurs in Hashimoto's thyroiditis at some point. Symptoms from low thyroid hormone are usually what cause a person to see the doctor.
In some cases, the thyroid hormone may actually be high, which causes almost opposite symptoms. For example, weight loss, fast heartbeat, diarrhoea, and moist skin can occur.
What are the causes and risks of the disease? The exact cause of Hashimoto's thyroiditis is not known. As with all autoimmune disorders, the immune system abnormally attacks the body. Hashimoto's thyroiditis also occurs more often in some people with other autoimmune disorders and diabetes.
What can be done to prevent the disease? Nothing can be done to prevent the disease because the exact cause is not understood.
How is the disease diagnosed? The doctor will take a history and complete a physical examination. The doctor will usually order blood tests, including thyroid function tests and a full blood count, or FBC. Additional blood tests or special X-ray tests can usually confirm the diagnosis of Hashimoto's thyroiditis.
Sometimes a thyroid fine needle biopsy may be needed. This biopsy involves getting a small sample of the thyroid gland with a special needle inserted through the skin. This sample can be examined under a microscope to make the diagnosis.
What are the long-term effects of the disease? Hashimoto's thyroiditis often causes low thyroid hormone levels, or hypothyroidism. This may be permanent, requiring thyroid hormone replacement medication for life.
What are the risks to others? There are no risks to others, as this disease is not contagious.
What are the treatments for the disease? Treatment generally focuses on the level of thyroid hormone. If the level is low, as it is in most cases, thyroid hormone pills are needed. If the thyroid level is high, other medications are needed to block thyroid hormone from working in the body. Rarely, surgery may be needed if the thyroid gland gets too big.
What are the side effects of the treatments? All medications have side effects. If too much thyroid medication is given, the levels can become toxic. Medications used to treat abnormal thyroid levels may cause allergic reactions, stomach upset, or other side effects. Surgery carries a risk of bleeding, infection, and allergic reaction to the anaesthesia.
What happens after treatment for the disease? A person with Hashimoto's disease often requires monitoring and treatment for life.
How is the disease monitored? Periodic thyroid function tests and visits to the doctor are recommended to monitor the course of the disease.
Author: Adam Brochert, MD Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request
