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Hashimoto's thyroiditis is an autoimmune disorder that damages the thyroid gland. Autoimmunity occurs when immune cells attack healthy tissue instead of protecting it, leading to chronic inflammation.
In Hashimoto's thyroiditis, immune cells mistakenly attack the healthy thyroid tissue, causing inflammation of the thyroid. This damage can eventually lead to inadequate thyroid hormone production. Without enough thyroid hormones for your body to function correctly, you develop hypothyroidism.
Hashimoto's thyroiditis is the leading cause of hypothyroidism in the United States, affecting roughly 5% of the population.
Doctors aren't entirely sure why the immune system, which is supposed to defend the body from harmful viruses and bacteria, sometimes turns against the body's healthy tissues.
Some scientists think a virus or bacterium might trigger the response, while others believe it may involve a genetic flaw. A combination of factors—including heredity, sex, and age—may determine your likelihood of developing the disorder.
Researchers estimate that 70%–80% of autoimmune thyroid disease susceptibility is from a family history of autoimmune disease.
Pregnancy puts metabolic stress on a woman. The thyroid undergoes noticeable modifications to cope. These changes are typically reversible after birth, though pregnancy can sometimes be a trigger for postpartum thyroiditis. Postpartum thyroiditis is a condition in which the thyroid becomes inflamed within the first year after birth. In most cases, postpartum thyroiditis is limiting to weeks or months after delivery but occasionally develops into Hashimoto's disease.
Other hormonal events
Hashimoto's is seven times more likely to occur in women than men. Hormonal events like puberty, pregnancy, or menopause may contribute to the development of Hashimoto's.
It is not uncommon for someone with one autoimmune condition to have another like celiac disease, type one diabetes, rheumatoid arthritis, or lupus. This condition of have two or more autoimmune disorders is polyautoimmunity.
Emotional or physical stress
Emotional stress can come from feelings of resentment, fears, frustration, sadness, anger, or grief. Physical stress can come from over or undereating, over or underexercising, smoking, or other bad habits. According to the American Psychological Association, chronic stress may affect the immune system.
The more dietary stress you put on yourself, the more likely you are to experience inflammation. Inflammation can worsen your autoimmune reactions and interfere with your thyroid function. Common deficiencies include selenium, vitamin D, nutrient-poor diets, B vitamins, iron/ferritin, iodine, and zinc.
Dietary triggers can lead to increased gastrointestinal permeability, chronic inflammation, and a possible elevation in thyroid antibodies. Common sensitivities include gluten, dairy, soy, grains, eggs, nuts and seeds, and nightshade vegetables.
Environmental exposure to toxicants may cause susceptibility to autoimmune thyroid disease. Common toxins include plastic water bottles (BPA), pesticides, antibacterial in soaps, fertilizer, smoking, and soy products.
As part of the endocrine system, the thyroid gland produces hormones that regulate your body's energy use, along with many other essential functions. When your thyroid hormone production drops, your body processes slow down and change, affecting virtually every system in your body.
Common symptoms of hypothyroidism include:
- Increased sensitivity to cold
- Puffy face
- Muscle weakness
- Elevated blood cholesterol level
- Muscle aches, tenderness, and stiffness
- Pain, stiffness, or swelling in your joints
- Heavy or irregular menstrual periods
- Thinning hair
- Slowed heart rate
- Impaired memory
- Enlarged thyroid gland (goiter)
Causes of hypothyroidism
There can be many reasons why the thyroid gland may not produce enough thyroid hormone, including:
- Autoimmune disease
- Surgical removal of part of all of the thyroid gland
- Radiation treatment
- Congenital hypothyroidism (being born with hypothyroidism)
- Thyroiditis (inflammation of the thyroid gland, usually caused by an autoimmune attack or viral infection)
- Certain medicines
- Too much or too little iodine
- Damage to the pituitary gland
- Rare disorders that infiltrate the thyroid
As seen on that list, autoimmune disease is the most common cause of hypothyroidism. Indeed, Hashimoto's thyroiditis is the leading cause of hypothyroidism in the United States.
So, the difference between Hashimoto's thyroiditis and hypothyroidism is that hypothyroidism is the state of an underactive thyroid, whereas Hashimoto's is an autoimmune condition that can cause hypothyroidism. Essentially, hypothyroidism is a problem with your thyroid gland. Hashimoto's is a problem with your immune system. You can have one condition without the other. However, they commonly come hand-in-hand without early detection of the TPO antibodies present in Hashimoto's.
In the early stages, the body compensates and produces more hormones to keep your hormone levels within "normal" ranges. Here, your thyroid is still close to fully functional. While TPO antibodies may be present in the blood, marking the presence of an autoimmune condition, it could take several years before hypothyroid symptoms appear.
Progressively, as TPO antibodies destroy more thyroid tissue, the thyroid gland loses the ability to compensate. You begin to become deficient in thyroid hormone, and you might start to feel symptoms.
Eventually, the gland completely loses its ability to produce thyroid hormone, considered the end-stage of Hashimoto's thyroiditis.
You might not notice signs or symptoms of Hashimoto's disease at first, or you may see swelling at the front of your throat (goiter). Hashimoto's disease typically progresses slowly over the years. It causes chronic thyroid damage, leading to a drop in thyroid hormone levels in your blood.
As Hashimoto's destroys more thyroid tissue, the drop in thyroid hormone production may express symptoms similar to hypothyroidism including:
- Tiredness and fatigue
- Weight gain
- Trouble tolerating cold
- Joint and muscle pain
- Dry, thinning hair
- Heavy or irregular menstrual periods and problems becoming pregnant
- Feelings of depression
- Memory problems
- Slowed heart rate
The thyroid becomes less and less capable of compensating for its thyroid hormone deficiency. In the end stages of Hashimoto's thyroiditis, the gland loses its ability altogether to produce thyroid hormone.
If you experience Hashimoto's symptoms, a complete blood test can help you understand how your thyroid works.
Without verifying the presence of thyroid antibodies, these symptoms (or lack thereof) can lead to a missed diagnosis or misdiagnosis.
The diagnosis of Hashimoto's thyroiditis comes from laboratory testing and physical examination. What you most commonly find in bloodwork that indicates Hashimoto's is elevated TSH and low T4 (thyroxine), in conjunction with elevated TPO antibodies.
Your complete thyroid blood panel should include TSH, free triiodothyronine (fT3), free thyroxine (fT4), and TPO antibodies. Having this information helps to determine the cause of your under- or over-active thyroid.
Lab results read as "positive" or "negative" concerning whether you have TPO antibodies present in your blood sample.
Suppose you show a negative result for TPO antibodies. In that case, it means that there were no TPO antibodies discovered in your blood. Therefore, if you have symptoms of a thyroid condition, it is unlikely that an autoimmune disorder causes them.
If you show a positive result for TPO antibodies, it may mean you have:
The diagnosis is made if you have high levels of TPO antibodies and high levels of thyroglobulin (Tg) - a protein produced by the thyroid.
The diagnosis is made if you have high levels of TPO antibodies and high levels of thyroid-stimulating hormone (TSH) receptor antibodies.
A TPOAb test is not the only indicator of Hashimoto's. A study from California Northstate University suggests that 10% of patients with Hashimoto's may have negative blood work for TPO antibodies.
While there is a low probability that you need other tests to confirm Hashimoto's disease, a thyroid ultrasound can help diagnose, if necessary. The ultrasound assesses the size of the thyroid, the pattern and structure of tissue, and the presence of nodules.
Use the same laboratory
Autoimmunity and the degree to which your immune system attacks your thyroid can vary much day-to-day. It is also highly sensitive to your lifestyle, including diet, stress, sleep, and exercise. The measure of antibodies can vary based on what's going on in your environment.
Thyroid blood test results are only meaningful when compared to reference ranges. Reference ranges (or "normal" ranges) are the values expected for a healthy person.
Reference ranges vary by lab, meaning that different labs may yield different results. That is normal. Lab testing accuracy has significantly evolved. However, some lab-to-lab variability can still occur due to differences in testing equipment, chemicals used, and analysis techniques. This variability is the reason you should use the range supplied by the lab that analyzed your test to evaluate whether your results are within normal limits.
Use the same laboratory each time you have your labs drawn. Consistency is key.
Antibodies are proteins produced by the body to protect against infections. However, sometimes they mistakenly attack your tissues, causing illness.
Thyroid peroxidase (TPO) is an enzyme found in the thyroid gland that plays a vital role in producing thyroid hormones. TPO converts iodide ions absorbed from food into an active form of iodine to be used by the body.
The body needs iodine to make thyroid hormones. Iodine connects with tyrosine (an amino acid) for the production of the thyroid hormones: thyroxine (T4) and triiodothyronine (T3). If dietary iodine is deficient, the thyroid cannot produce sufficient thyroid hormone.
This lack of thyroid hormone creates negative feedback with the pituitary gland, which produces and releases thyroid-stimulating hormone (TSH). An increase in TSH signals additional production of TPO.
If antibody levels in the blood are elevated, it suggests that your immune system is attacking normal, healthy tissue.
Typically, the immune system safeguards against germs like bacteria and viruses. It can generally distinguish between foreign cells and your cells.
However, autoimmunity is a condition in which your immune system mistakenly attacks your body. It mistakes your cells as foreign and releases antibodies that attack healthy cells.
Some autoimmune conditions target only one part of the body, like Hashimoto's thyroiditis (or autoimmune thyroiditis), which targets the thyroid gland.
Can I have thyroid antibodies without hypothyroidism?
In many cases, thyroid antibodies can be the first indication of a thyroid problem. The presence of thyroid antibodies in the blood does not necessarily mean that a person has fully-developed hypothyroidism. However, it does mean that there is an ongoing attack against the thyroid. This attack increases your risk for future thyroid disorders.
Patients with elevated TPO antibodies but normal thyroid function tests (TSH and Free T4) do not necessarily require treatment. Similarly, patients with only slightly elevated TSH may not require thyroid hormone medication, either. They should repeat testing after 3-6 months to monitor thyroid status.
Overt hypothyroidism (elevated TSH and low thyroid hormone levels), however, can be controlled by replacing the amount of thyroid hormone that your thyroid gland can no longer make with thyroid hormone replacement medication. Hypothyroidism is not curable, but you can take medication to bring your TSH and thyroid hormone levels back to normal.
Nearly all hypothyroid patients can be treated as outpatients, not having to admit to the hospital.
Most patients with hypothyroidism will require lifelong treatment with thyroid hormone replacement medication. Finding the appropriate dose, particularly at the beginning, may require some trial-and-error. You should test thyroid levels every 6-8 weeks after any dose adjustment until achieving the correct dose. After that, testing your thyroid once a year is generally sufficient.
When on the appropriate dose of thyroid hormone replacement medication, it has no side effects. However, suppose your dose of medicine is too high or too low. In that case, serum TSH levels remain affected, and patients may have persistent symptoms.
Nutrition matters. What you eat may affect your thyroid disease, including the absorption of your thyroid medication. Nutrition, supplements, and lifestyle optimization have been shown to make a difference in some instances and are personal to each patient. Talk to a Paloma Health thyroid nutritionist for more details about how personalized dietary guidance and health coaching might benefit you.
While you cannot reverse autoimmune disease, you can stall progression. A healthy diet and exercise routine helps to limit the progress of the disease. There is no cure for Hashimoto's, so proactively monitoring and adjusting your treatment plan is critical to feeling your best each day.
High levels of TPO antibodies may be indicative of autoimmune thyroid disease. On their own, the presence of TPO antibodies does not necessarily mean hypothyroidism. Instead, Hashimoto's is the most common cause of hypothyroidism. So the presence of thyroid antibodies may predict the risk of developing hypothyroidism, and it may be advantageous to lower antibodies to protect your thyroid gland.
Ahead, a few strategies to help reduce TPO antibodies:
Try a Paleo or Autoimmune Protocol diet
Common food sensitivities include gluten, dairy, soy, grains, eggs, nuts, seeds, and nightshades. The Autoimmune Protocol (AIP) diet is a way of eating that helps you identify which of these foods may be triggering inflammation in your body. One study of 17 women between the ages of 20-45 who participated in a ten-week Autoimmune Protocol program shows that identifying your dietary triggers may decrease systemic inflammation and modulate the immune system.
Supplement with vitamin D
Vitamin D supplementation may reduce TPO antibody levels. One study of 102 patients with newly diagnosed autoimmune thyroid disease shows a significant reduction in TPO antibodies after three months of vitamin D supplementation.
Supplement with selenium
Selenium supplementation may also reduce TPO antibody levels. One blind, placebo-controlled study of women with autoimmune thyroiditis suggests that selenium supplementation may improve inflammation.
Address other nutrient deficiencies
Other common nutrient deficiencies include B vitamins, iron or ferritin, iodine, or zinc. Work with your doctor to confirm any nutrient deficiencies with lab testing. It is easy to treat with the appropriate supplements.
Remove or avoid environmental toxins
Although about 70% of the risk for developing autoimmune thyroid disease is due to family background, several environmental toxins like radiation, iodine excess, pesticides, or chemical exposure may still trigger TPO antibodies.
Manage your stress
Stress is anything that disrupts the body's natural balance (homeostasis), so while this advice may sound trite, stress can affect virtually every system in your body. Stress can be anything from significant life shifts or a heavy workload to blood sugar imbalance, too much exercise, reduced sleep quality, environmental toxins, and more.
Get enough sleep
Not only is sleep important for your overall health, but it's also a powerful form of treatment for autoimmune conditions. Adequate sleep can lower inflammation, heal, and restore damaged tissue.
A note from Paloma Health
The path to thyroid health and well-being can feel painful, long, and frustrating—and it shouldn't have to be this way! We recommend you work with a trustworthy thyroid doctor to find the optimal functioning of your thyroid. Schedule a free consultation with a care advisor to determine if Paloma Health might be the right fit for you.
The above information is not a diagnosis, treatment, cure for thyroid disease. We recommend that you work with your Paloma Health care team to learn how to optimize your thyroid health.