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Your thyroid, a butterfly shaped gland, sits at the base of your neck and releases thyroid hormones: thyroxine (T4) and triiodothyronine (T3). These hormones help regulate your metabolism, growth, and development.
A feedback loop called the hypothalamus-pituitary-thyroid (HPT) axis regulates thyroid hormone production. This loop starts in your hypothalamus with the release of thyrotropin-releasing hormone (TRH). In response, your pituitary gland releases thyroid stimulating hormone (TSH). TSH travels to your thyroid gland, telling it to release T3 and T4. As thyroid hormone enters your cells, levels in your blood drop. This triggers your hypothalamus to release TRH, and the loop continues.
A change in your HPT axis can change your thyroid production, resulting in the following:
- Hyperthyroidism: overproduction of thyroid hormone
- Hypothyroidism: underproduction of thyroid hormone
Graves’ disease and Hashimoto’s are two thyroid-related medical disorders resulting from changes in thyroid hormone production. Let’s compare these two medical conditions to better understand their similarities and differences.
Your immune system’s primary role is to keep you healthy by preventing or fighting off infections. It does this by attacking foreign invaders like germs and viruses when they enter your body. After attacking them, your immune system develops antibodies against them. These antibodies allow your body to identify and destroy them if they enter again.
Sometimes, and not always for clear reasons, your immune system becomes overstimulated. This overstimulation leads to the production of antibodies against your own healthy cells. These antibodies either destroy your cells or cause them to work overtime.
In Hashimoto’s, antibodies destroy thyroid cells. This leads to an underproduction of thyroid hormone. The primary antibodies seen in Hashimoto’s are thyroid peroxidase and thyroglobulin antibodies. Even if you have these antibodies, it doesn’t mean you have overt Hashimoto’s. Sometimes these antibodies are present at low enough levels that they don’t affect your thyroid function. Your healthcare provider will look at other lab values like TSH and T4 levels to diagnose Hashimoto’s.
On the other hand, thyrotropin receptor antibodies stimulate thyroid cells to work overtime in those with Graves’ disease. Because of this, thyroid cells produce and release too much thyroid hormone causing hyperthyroidism.
Since thyroid hormone regulates our metabolism, symptoms of autoimmune thyroid diseases typically reflect having too much or too little energy.
In Hashimoto’s, the amount of thyroid hormone produced from the thyroid gland decreases over time. Having too little thyroid hormone causes our bodies to slow down, leading to symptoms of:
- Cold intolerance
- Dry skin
- Hair loss
- Weight gain
In contrast, people with Graves’ disease have too much thyroid hormone, resulting in extra energy. Because of this, your body functions speed up. An overactive thyroid can cause symptoms, including:
- Bulging eyes (Graves’ eyes, or thyroid eye disease)
- Difficulty sleeping
- Graves’ dermopathy (reddening and thickening of the skin)
- Hand tremors
- Increased heart rate and irregular heartbeats
- Weight loss
- Diarrhea and frequent bowel movements
But Hashimoto’s and Graves’ disease share some signs and symptoms, including the following:
- Goiter or swelling of the thyroid gland
- Muscle weakness
- Changes to menstrual cycles
- Mental health changes, like depression and anxiety
While shared, there are different reasons these symptoms and signs occur. For instance, in Hashimoto’s, you may feel tired due to a lack of energy. In contrast, those with Graves’ disease may see an initial spike in energy levels, but lack of sleep and a racing metabolism associated with consistently high thyroid levels can cause fatigue.
The treatment goal for both Hashimoto’s and Graves’ disease is to achieve a normal thyroid hormone level. In doing this, your cells can return to functioning correctly.
Even with proper treatment, thyroid disorders can’t be cured. But instead, they are managed with the below therapies.
For those with Hashimoto's, thyroid hormone levels need to increase. The most studied way to do this is by taking thyroid hormone replacement medications. There are several thyroid hormone replacement therapies, including the following:
- Levothyroxine (LevoxylⓇ, SynthroidⓇ) - a synthetic form of T4
- Liothyronine (CytomelⓇ) - a synthetic form of T3
- Armour thyroidⓇ - a combination of T4:T3 of natural desiccated thyroid
While there is one primary treatment for Hashimoto’s, those with Graves’ disease have several options:
- Antithyroid medications. These medications block your thyroid gland from making thyroid hormones. Methimazole (TapazoleⓇ) or propylthiouracil are two of these medications, with methimazole preferred due to fewer side effects. These medications won’t damage your thyroid gland.
- Radioactive iodine. When your thyroid cells absorb radioactive iodine, the iodine destroys those cells. This prevents them from making and releasing thyroid hormones. For most, thyroid hormone levels drop to within a normal range after one treatment. But some may need another course if they remain hyperthyroid. Most develop hypothyroidism after radioactive iodine treatment, requiring management with thyroid hormone replacement medications.
- Surgery. A surgeon can remove all or most of your thyroid gland. This causes hypothyroidism, requiring lifelong treatment with thyroid hormone replacement medication.
- Beta-blockers. This class of medications includes propranolol, atenolol, and metoprolol. They help with your symptoms of hyperthyroidism by slowing your heart rate and controlling shakiness. But they do not affect your thyroid hormone levels.
The decision to treat either Graves’ disease or Hashimoto’s isn’t solely based on the presence of antibodies. Your thyroid provider will look at your medical history, symptoms, and your thyroid function lab values. Paloma Health’s at-home testing kit allows you to test your thyroid function from the comfort of your home.
Our Paloma Health thyroid specialists can walk you through the meaning of your labs and treatment options, and create a treatment plan for your underactive thyroid. Make a virtual appointment to see one of them today.