Type 1 hypothyroidism and Type 2 hypothyroidism – what’s the difference?
- Type 1 hypothyroidism is characterized by an under active thyroid that doesn’t produce enough thyroid hormone.
- Type 2 hypothyroidism is characterized by a perfectly normal thyroid that produces exactly the right amount of thyroid hormone it’s supposed to. However, cells are not able to use the hormone correctly. It’s commonly referred to as thyroid hormone resistance.
Symptoms of Type 2 Hypothyroidism
The symptoms of thyroid hormone resistance (type 2) are exactly the same as those for other types of hypothyroidism. This is because your cells can’t use the thyroid hormones properly or in sufficient quantities. And when your cells can’t actually use thyroid hormone the end result is just the same as if your thyroid gland wasn’t producing enough. You have hypothyroidism so you’ll have the same symptoms! There is more information about the symptoms of hypothyroidism here.
Diagnosing Type 2 Hypothyroidism
In a normal healthy person their HPT axis functions as it should. As cells need more thyroid hormone they send a message to the hypothalamus, which then tells the pituitary to tell the thyroid (via TSH) to produce more hormones. The thyroid does so. The thyroid hormone is distributed to the cells by the blood. The cells reduce their signals to the hypothalamus and the pituitary stops producing TSH. This cycle is what the standard blood test for hypothyroidism, which measures levels of TSH and thyroid hormone in the blood, is based on.
One of the issues with Type 2 hypothyroidism though is that because the levels of these hormones circulating in the blood are perfectly normal, standard tests for hypothyroidism miss it. The tests don’t pick up defective or toxic cells that can’t signal the hypothalamus correctly or cells with thyroid hormone receptors that have become resistant to regular levels of hormone.
Diagnosing Type 2 Hypothyroidism EFFECTIVELY
Therefore, the only way to effectively diagnose Type 2 hypothyroidism is by assessing the patient’s history and clinical symptoms together with their basal temperature. The basal temperature test was figured out by Broda Barnes MD, who got his patients to take their armpit temperature every morning for a period of weeks before getting up. If their average basal temperature over that period of time was less than 97.8º F they were likely to be hypothyroid. This connection between a persistent lower than normal basal temperature and hypothyroidism has proven to be fairly accurate. However, if there is severe inflammation present causing a raised temperature this may hide a low basal temperature so this test is not completely infallible either.
Interesting Questions about Thyroid:
As with any disease, it is important that you watch for the early warning signs of hyperthyroidism. However, only your doctor can tell for sure whether or not you have the disease. Your doctor may examine:
- your history and physical appearance
- the amount of thyroid hormones, thyroid stimulating hormone (TSH), and thyroid stimulating antibodies in your blood
- the structure and function of your thyroid gland, using thyroid imaging, which takes a picture of the gland after you have been given a small amount of radioactive iodine
The basic goal of treatment is to return thyroid hormone levels to normal.
Hyperthyroidism makes the body work too fast because there is too much thyroid hormone in the blood. Graves’ disease is the most common cause of hyperthyroidism. Graves’ disease occurs because of a problem in the body’s immune system: antibodies are produced that overstimulate the thyroid gland.
Patients who are hyperthyroid from taking too much thyroid hormone need only to have their dosage properly adjusted.
Patients whose hyperthyroidism is caused by transient thyroiditis usually do not require any of the treatments described below, since their condition gets better on its own.
Treatment for hyperthyroidism from Graves’ disease, toxic autonomously functioning thyroid nodule, or toxic multi-nodular goiter may include one or more of the following:
Radioactive iodine (I131)
Radioactive iodine shrinks an enlarged thyroid or toxic nodule or nodules that are making too much thyroid hormone. This treatment is safe and is widely used in adults with hyperthyroidism.
* Radioactive iodine (I131) is the treatment of choice for the majority of the endocrinologists in this country. It is an effective, simple, safe way to treat patients with Graves’ disease or other forms of hyperthyroidism. Patients often have fears and misconceptions about using radioactive iodine.
* Studies have been done since the 1940’s on patients receiving this treatment. Treated patients, their children, and their grandchildren do not have an increased incidence of cancer, leukemia, etc.
* There are no increased instances of birth defects in children born to mothers who have had this treatment and waited the recommended time before becoming pregnant. (Pregnancy should be avoided for at least six months after the treatment.) As a matter of fact, fertility is often restored to women whose infertility is due to hyperthyroidism. Treating the disease also lessens the chance of miscarriage.
* Pregnant women should not be given radioactive iodine for any reason. If a patient has any doubt as to whether she is pregnant, treatment (and testing) with radioactive iodine should be delayed.
* Hospitalization is not required in order to treat hyperthyroidism with radioactive iodine.
* Radioactive iodine treatment ablates the thyroid gland (turns it into something like a dried-up raisin). Patients wishing to avoid destruction of the gland should know that the thyroid gland frequently “burns out” within 15 years even without treatment.
* Radioactive iodine does not cause a person to gain weight. However, because Graves’ disease increases the metabolism, patients should keep in mind that they cannot continue to eat the way they did while hyperthyroid. Because of changes in the metabolism after hyperthyroidism is treated, many patients will gain weight . This weight can be lost through diet and exercise once the thyroid levels are normalized.
Antithyroid drugs, such as propylthiouracil (PTU) and methimazole (Tapozole®), are used in patients with Graves’ disease and, less commonly, in other hyperthyroid patients
In some cases beta-blocking drugs are prescribed to treat the symptoms of hyperthyroidism while waiting for one of the above treatments to work.
Your doctor will be able to discuss the benefits and risks of each treatment.
Many patients treated for hyperthyroidism become hypothyroid. They will need to take thyroid hormone pills for the rest of their lives. In addition, they will need to see their doctor at least once a year.
® Tapozole is a registered trademark of Jones Medical Industries.
Possible effects of hypothyroidism are:
- slow heart rate (less than 70 beats per minute)
- elevated blood pressure
- feeling slow or tired
- feeling cold
- drowsy during the day, even after sleeping all night
- poor memory
- difficulty concentrating
- muscle cramps, numb arms and legs
- weight gain
- puffy face, especially under the eyes
- husky voice
- thinning hair
- dry, coarse, flaky, yellowish skin
- in children, short height
- heavy menstrual flow
- milky discharge from the breasts
- goiter (an abnormal swelling in the neck caused by an enlarged thyroid gland).
Have more questions? Need more answers? Check our Full Thyroid FAQ
Treating Type 2 Hypothyroidism
As with other types of hypothyroidism, the treatment for Type 2 hypothyroidism is with replacement hormone therapy. It may seem contraindicated to be treating someone with normal levels of thyroid hormone with more hormone. The idea though is that eventually, when the cells are flooded with enough hormone for long enough, they do begin to start processing and using hormone correctly again. And once this happens, the body has a remarkable ability to self-correct. Particularly if other life-style changes like a good diet containing essential nutrients required by the thyroid, exercise and removing / reducing access to toxins that may have caused the cellular dysfunction are implemented at the same time. At this point hormone therapy may be able to be tapered off. Therefore Type 2 hypothyroidism patients should be carefully monitored for improvements in symptoms and a rise in basal temperature. These usually indicate cells are beginning to take in and use thyroid hormone again.
Hormone Replacement Therapy For Type 2 Hypothyroidism
Natural vs Synthetic. The common type of hormone replacement for all types of hypothyroidism is a synthetic T4 replacement but traditionally desiccated or powdered pig thyroid was used. Some practitioners still prescribe this because it contains the entire thyroid gland, including all 4 thyroid hormones (T3, T4, T2 and T1) as well as other important thyroid compounds. This provides a more synergistic treatment. You could compare it with getting your nutrition naturally from food rather than popping pills.
Research has shown that many patients do experience marked improvement after swapping from artificial hormones to natural desiccated thyroid extract (DTE). However, and this is important to understand – thyroid treatment programs need to be tailored to each individual patient. What works for one person may not work for someone else. T4 needs to be converted to T3 by the body and some people can’t do this effectively. Therefore they require T3. Some people need both T4 and T3. And so on. Some patients do better on synthetic hormones, others do better on DTE. Some patients have religious beliefs that prohibit them from consuming pork products. Others, like vegans and vegetarians, don’t eat meat or any animal derived products. DTE is not an option for these people.
Detox Therapy For Type 2 Hypothyroidism
Studies like this one and others cited in the study show that contamination from heavy metals like mercury, lead and cadmium can adversely affect the body’s ability to take up and utilize thyroid hormones. Therefore, some practitioners recommend detox therapy as part of the treatment regime for hypothyroidism patients, notably those in which toxin build ups may be contributing to cellular abnormalities that hinder uptake of thyroid hormones.
Nutrition For Type 2 Hypothyroidism
Good nutrition is the basis for good health period. People with thyroid disorders particularly need to ensure their diet is rich in thyroid essential nutrients, notably iodine, selenium and zinc.