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Your thyroid gland produces hormones that help your body function and use energy. When your thyroid hormone production drops, everything slows down, including all your organs, glands, tissues, and cells.
While there are many causes of a slow or underactive thyroid, we will focus on one: Hashimoto’s thyroiditis, an autoimmune disease. Ahead, learn more about Hashimoto’s thyroiditis and the role of its chief biomarker: elevated thyroid peroxidase (TPO) antibodies.
Hashimoto’s thyroiditis is an autoimmune endocrine disorder resulting in chronic thyroid gland inflammation. This occurs when the immune system mistakenly attacks healthy thyroid tissue. As a result of the damage, thyroid hormone production drops. Without enough thyroid hormone for your body to function correctly, you develop a medical condition called hypothyroidism. Hypothyroidism is defined as an underactive thyroid condition.
Essentially, Hashimoto’s thyroiditis is a disease of your immune system. Hypothyroidism is a condition that affects your thyroid gland. You can have one without the other. Yet, they commonly go hand-in-hand.
Hashimoto’s is the leading cause of hypothyroidism in the United States, affecting roughly 5% of the population. Because Hashimoto’s results in hypothyroidism, both conditions share the same symptoms of an underactive thyroid, such as:
- Tiredness and fatigue
- Weight gain
- Trouble tolerating cold
- Joint and muscle pain
- Constipation
- Dry, thinning hair
- Heavy or irregular menstrual periods
- Infertility
- Feelings of depression
- Memory problems
Experts are still determining why the immune system, which is supposed to defend the body from harmful viruses and bacteria, sometimes turns against the body’s healthy tissues and organs.
Some experts think a virus or bacterium might trigger the response, while others believe it may involve a genetic characteristic. An estimated 70 to 80% of those with an autoimmune thyroid disorder either have a family history of a thyroid disorder or a personal history of another autoimmune disorder such as celiac disease or rheumatoid arthritis.
Despite the strong genetic link, it’s likely that a combination of factors – including environmental (stress, diet, toxins), sex, and age – determine your likelihood of developing 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 often progresses slowly. Over time, it causes chronic thyroid damage, leading to a drop in thyroid hormone levels in your blood.
In the early stages, the body compensates and produces more thyroid hormone to keep your levels within “normal” ranges. At this point, your thyroid is still close to fully functional. While TPO antibodies may be present in the blood, it can take several years before hypothyroid symptoms appear.
As TPO antibodies destroy more thyroid tissue, the thyroid gland loses the ability to compensate. You begin to become deficient in thyroid hormone and may start to feel hypothyroid 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, known as goiter. Hashimoto’s disease often progresses slowly through various stages. Over time, it can cause thyroid damage, leading to a drop in thyroid hormone levels in your blood.
In the early stages, the body compensates and produces more thyroid hormone to keep your levels within “normal” ranges. At this point, your thyroid is still close to fully functional. While antibodies may be present in the blood, it can take several years before hypothyroid symptoms appear.
As TPO antibodies destroy more thyroid tissue, the thyroid gland loses the ability to compensate. You begin to become deficient in thyroid hormone and may start to feel hypothyroid symptoms.
Eventually, the gland usually loses its ability to produce thyroid hormone. This complete shut-down is considered the end-stage of Hashimoto’s thyroiditis.
Thyroid peroxidase (TPO) is an enzyme in the thyroid gland that plays a vital role in producing thyroid hormones. TPO helps synthesize thyroid hormones – triiodothyronine (T3) and thyroxine (T4) – using iodide ions absorbed from food into an active form of iodine. The body needs this iodine to make the thyroid hormones thyroxine (T4) and triiodothyronine (T3).
Antibodies are proteins the body produces to protect against foreign invaders such as germs. But, sometimes, the body develops antibodies against healthy cells. In general, an elevated antibody level in the blood suggests that your immune system is attacking normal, healthy tissue. This results in either destruction of the healthy cells or, in some cases, activates excessive hormone secretion.
Thyroid peroxidase (TPO) antibodies are proteins produced by the immune system. These proteins mistakenly target the thyroid gland’s enzyme, thyroid peroxidase. Since TPO is mainly found in your thyroid cells, TPO antibodies are frequently a sign of an autoimmune thyroid disorder.
There are two autoimmune thyroid disorders. We have already discussed Hashimoto’s thyroiditis. The second is Graves’ disease, which results in an overactive thyroid (hyperthyroidism). TPO antibodies can be present in both thyroid autoimmune disorders; however, symptoms of these two thyroid autoimmune disorders differ.
Both conditions share common symptoms like fatigue, muscle weakness, and changes in menstrual cycle. Otherwise, many of the symptoms are quite different. Hashimoto’s slows the metabolism, leading to symptoms such as fatigue, weight gain, cold intolerance, depression, constipation, dry skin, and hair loss. Hashimoto’s disease is also associated with an increased risk of developing a goiter, which is an enlarged thyroid gland.
In contrast, Graves’ disease results in hyperthyroidism. This overactive thyroid condition speeds up the metabolism, leading to symptoms such as weight loss, rapid heartbeat, anxiety, tremors, sweating, difficulty sleeping, and frequent bowel movements. Graves’ disease can also cause unique symptoms such as bulging eyes (Graves’ ophthalmopathy) and skin thickening (Graves’ dermopathy).
Hashimoto’s disease is diagnosed through a combination of medical history, physical examination, and specific blood tests.
Doctors begin by reviewing the patient’s medical history and conducting a physical exam. They look for symptoms such as fatigue, weight gain, and muscle weakness and check for an enlarged thyroid gland (goiter), which can indicate Hashimoto’s disease.
Several blood tests are also crucial for diagnosing Hashimoto’s thyroiditis, including:
- Thyroid stimulating hormone (TSH): This test measures the level of TSH in the blood. High levels of TSH indicate that the thyroid is not producing enough hormones, a condition known as hypothyroidism.
- Free thyroxine (free T4): This test measures the free and unbound level of thyroxine (T4), the main hormone produced by the thyroid. Low levels of Free T4 can confirm hypothyroidism.
- Thyroid peroxidase antibodies: When elevated above the reference range, the presence of these antibodies is a hallmark of Hashimoto’s.
Additional tests: A thyroid ultrasound may be performed if the diagnosis is uncertain or no antithyroid antibodies are present. This imaging test can show the size of the thyroid and detect any abnormalities, such as nodules.
Lab results will read as “positive” or “negative” on whether you have TPO antibodies in your blood sample, along with an antibody level indicated with a number.
If your antibody level falls within the reference range, your result will be negative. In this case, TPO antibodies weren’t elevated enough to indicate autoimmune thyroid disease, and it is unlikely – but not impossible – that an autoimmune thyroid condition is the cause.
If your antibody levels are elevated above the reference range, you are “positive.” In that case, it may mean you have an autoimmune thyroid disorder such as Hashimoto’s or Grave’s disease.
For a Hashimoto’s diagnosis, you’ll typically have the following blood test results:
- an elevated TSH level
- low free T4 level
- positive/elevated TPO antibodies
People with Hashimoto’s will also frequently test positive for high levels of thyroglobulin (Tg) – a protein produced by the thyroid.
It is possible to have thyroid antibodies without being hypothyroid. Thyroid antibodies can be present in the blood without causing clinical hypothyroidism. This situation is often seen in individuals with early Hashimoto’s disease, where the immune system attacks the thyroid gland, but the gland still functions normally for a period of time.
Also, not everyone with Hashimoto’s disease develops hypothyroidism. Some individuals may have high antibody levels but do not exhibit the symptoms or clinical signs of hypothyroidism. These individuals are typically monitored regularly to check for any changes in thyroid function over time. Additionally, TPO antibodies can be present in more than 90% of patients with hypothyroidism and in about 10% of people who do not have a thyroid problem yet but may develop a future autoimmune issue.
Women with positive TPO-Ab levels face an increased risk of miscarriage, infertility, and preterm birth, even if their thyroid function appears normal and they are not diagnosed with hypothyroidism. These antibodies are also strongly associated with postpartum thyroid problems after pregnancy, including postpartum thyroiditis, which can persist for up to a year after delivery.
Additionally, positive antibodies increase the likelihood of developing subclinical hypothyroidism during pregnancy, a condition that requires careful management to avoid complications.
Given these risks, early screening for thyroid dysfunction, including testing for thyroid peroxidase antibodies, is recommended for pregnant women, typically between weeks 7 and 13 of gestation. This allows for timely intervention and close monitoring during and after pregnancy.
Management strategies may include regular thyroid function tests and, in some cases, treatment with levothyroxine to maintain optimal thyroid hormone levels.
Women planning to conceive or who are already pregnant should discuss thyroid screening and monitoring with their healthcare provider to ensure appropriate care and reduce the risk of adverse outcomes.
If you have elevated TPO antibodies but normal thyroid function tests (TSH and free T4), you may not need treatment. Similarly, if your TSH level is only slightly elevated (subclinical hypothyroidism), you may not need thyroid hormone medication either. In these cases, you should be monitored and have repeat testing every 3 to 6 months to evaluate your thyroid status.
Overt hypothyroidism (high TSH and low thyroid hormone levels) is managed 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 restore your TSH and thyroid hormone levels.
Most patients with hypothyroidism will require lifelong treatment with thyroid hormone replacement medication. Finding the appropriate dose may require trial and error, particularly at the start of treatment. Thyroid levels should be tested every 6 to 8 weeks after any dose change until the correct dose is achieved. After that, testing thyroid function once or twice a year is generally enough.
See what patients have to say about the Hashimoto's care they received from Paloma Health:
Remember: the presence of TPO antibodies doesn’t necessarily mean you are hypothyroid. But, they do put you at a greater risk of becoming hypothyroid in the future. And while you can’t reverse an autoimmune disorder, you can stall its progression and sometimes even achieve remission.
Lowering the level of TPO antibodies can help protect your thyroid gland. A healthy diet and exercise routine can help limit the disease’s progression. Here are six other ways to lower your TPO antibody levels:
- Try the Autoimmune Protocol (AIP) diet
- Supplement with vitamin D and selenium
- Address other nutritional deficiencies
- Heal leaky gut and other gut health issues
- Remove, avoid, or limit exposure to environmental toxins
- Try low-dose naltrexone (LDN) treatment
- Manage your stress
- Get enough sleep
Knowing how well your thyroid functions is the first step to improving your thyroid health and well-being. Most of the time, this involves visiting your local lab to have your thyroid blood panel drawn. If you take certain supplements like biotin, you may need to hold them a couple of days in advance to get accurate results.
But, at-home thyroid testing allows you to skip the lab visit. Paloma’s complete at-home testing kit will enable you to quickly and easily test your thyroid function from the comfort of your home. Our full thyroid panel includes TSH, free T4 and T3, and TPO antibodies. (You don’t have to stop biotin supplements in advance to get accurate results when testing with Paloma!)
We also recommend you work with a trustworthy thyroid doctor to optimize your treatment. Schedule a free consultation with a care advisor to determine if Paloma Health might be the right fit for you.
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