Hashimoto's disease is an autoimmune disorder affecting the thyroid gland. The thyroid is a butterfly-shaped gland located at the base of the neck just below the Adam's apple. The thyroid produces hormones that help regulate many functions in the body.
An autoimmune disorder is an illness caused by the immune system attacking healthy tissues. In Hashimoto's disease, immune-system cells lead to the death of the thyroid's hormone-producing cells. The disease usually results in a decline in hormone production (hypothyroidism).
Although anyone can develop Hashimoto's disease, it's most common among middle-aged women. The primary treatment is thyroid hormone replacement. Hashimoto's disease is also known as Hashimoto's thyroiditis, chronic lymphocytic thyroiditis and chronic autoimmune thyroiditis.
Symptoms of Hashimoto's diseaseHashimoto's disease progresses slowly over the years. You may not notice signs or symptoms of the disease. Eventually, the decline in thyroid hormone production can result in any of the following:
- Fatigue and sluggishness
- Increased sensitivity to cold
- Increased sleepiness
- Dry skin
- Constipation
- Muscle weakness
- Muscle aches, tenderness and stiffness
- Joint pain and stiffness
- Irregular or excessive menstrual bleeding
- Depression
- Problems with memory or concentration
- Swelling of the thyroid (goiter)
- A puffy face
- Brittle nails
- Hair loss
- Enlargement of the tongue
Cause of Hashimoto's disease
Hashimoto's disease is an autoimmune disorder. The immune system creates antibodies that attack thyroid cells as if they were bacteria, viruses or some other foreign body. The immune system wrongly enlists disease-fighting agents that damage cells and lead to cell death. What causes the immune system to attack thyroid cells is not clear. The onset of disease may be related to:
- Genetic factors
- Environmental triggers, such as infection, stress or radiation exposure
- Interactions between environmental and genetic factors
Risk factors
The following factors are associated with an increased risk of Hashimoto's disease:
- Sex. Women are much more likely to get Hashimoto's disease.
- Age. Hashimoto's disease can occur at any age but more commonly occurs during middle age.
- Other autoimmune disease. Having another autoimmune disease — such as rheumatoid arthritis, type 1 diabetes or lupus — increases your risk of developing Hashimoto's disease.
- Genetics and family history. You're at higher risk for Hashimoto's disease if others in your family have thyroid disorders or other autoimmune diseases.
- Pregnancy. Typical changes in immune function during pregnancy may be a factor in Hashimoto's disease that begins after pregnancy.
- Excessive iodine intake. Too much iodine in the diet may function as a trigger among people already at risk for Hashimoto's disease.
- Radiation exposure. People exposed to excessive levels of environmental radiation are more prone to Hashimoto's disease.
Diagnosis
A number of conditions may lead to the signs and symptoms of Hashimoto's disease. If you're experiencing any of these symptoms, your health care provider will conduct a thorough physical exam, review your medical history and ask questions about your symptoms.
Testing thyroid function To determine if hypothyroidism is the cause of your symptoms, your provider will order blood tests that may include the following:
- TSH test. Thyroid stimulating hormone (TSH) is produced by the pituitary gland. When the pituitary detects low thyroid hormones in the blood, it sends TSH to the thyroid to prompt an increase in thyroid hormone production. High TSH levels in the blood indicates hypothyroidism.
- T-4 tests. The main thyroid hormone is thyroxine (T-4). A low blood level of T-4 confirms the findings of a TSH test and indicates the problem is within the thyroid itself.
Treatment
Most people with Hashimoto's disease take medication to treat hypothyroidism. If you have mild hypothyroidism, you may have no treatment but get regular TSH tests to monitor thyroid hormone levels.
T-4 hormone replacement therapy Hypothyroidism associated with Hashimoto's disease is treated with a synthetic hormone called levothyroxine (Levoxyl, Synthroid, others). The synthetic hormone works like the T-4 hormone naturally produced by the thyroid.
The treatment goal is to restore and maintain adequate T-4 hormone levels and improve symptoms of hypothyroidism. You will need this treatment for the rest of your life.
Monitoring the dosage
Your heath care provider will determine a dosage of levothyroxine that's appropriate for your age, weight, current thyroid production, other medical conditions and other factors. Your provider will retest your TSH levels about 6 to 10 weeks later and adjust the dosage as necessary. T-3 hormone replacement therapy Naturally produced T-4 is converted into another thyroid hormone called triiodothyronine (T-3). The T-4 replacement hormone is also converted into T-3, and for most people the T-4 replacement therapy results in an adequate supply of T-3 for the body.
Alternative medicine
Products with T-3 and T-4 hormones derived from pigs or other animals are available as prescriptions or as dietary supplements, such as Armour Thyroid, in the United States. Concerns about these products include the following:
- The balance of T-4 and T-3 in animals isn't the same as in humans.
- The exact amount of T-4 and T-3 in each batch of a natural extract product can vary, leading to unpredictable levels of these hormones in your blood.
- Soy products
- High-fiber foods Iron supplements, including multivitamins that contain iron Cholestyramine (Prevalite), a medication used to lower blood cholesterol levels
- Aluminum hydroxide, which is found in some antacids
- Sucralfate, an ulcer medication
- Calcium supplements
Source
Hashimoto's disease - Symptoms and causes - Mayo Clinic