About Iatrogenic Hypothyroidism

The word “iastros” is an ancient term for ‘healer’ – Socrates for example was an ‘iastros tes psuches’ or ‘healer of the soul’.  “Genic” means ‘produced or caused by‘.  When you put these two words together you get ‘iatrogenic’ which literally means ‘healer caused or produced’.   Today it commonly refers to medical conditions or complications that have been brought on by treatments or advice given by members of the medical profession.  In the case of iatrogenic hypothyroidism, it means an under active thyroid condition that has been caused by some form of medical treatment or medical advice.  Iatrogenic hypothyroidism can be either permanent or reversible, depending on what has caused it and the extent of the damage done to the thyroid gland.

Iatrogenic Hypothyroidism – Common Causes

Drug (medication) induced hypothyroidism – as the name indicates, this form of iatrogenic hypothyroidism is caused by drugs or medication treatments that have been administered to a patient.  Some drugs used to treat hyperthyroidism, a condition in which the thyroid produces too much hormone, can cause hypothyroidism.  Amongst them are drugs like potassium iodide,  propylthiouracil and methimazole.

Other non-thyroid drugs used in treating other disorders can also cause drug-induced hypothyroidism. These include interleukin, lithium, amiodarone, sulfonylureas, nitroprusside, perchlorate, thalidomide and interferon-alpha therapy.

Iodine based topical antiseptics like povidone-iodine, better known as Betadine, can cause iatrogenic thyroid problems if enough of the iodine is absorbed by the body. Transient congential hypothyroidism is a case in point – povidone-iodine solutions are commonly used either during the birthing process, for treating the umbilical stump and for disinfecting the skin prior to treatment (injections or surgery).  If the infant absorbs enough of the iodine it can temporarily interfere with their thyroid function.  There are also documented cases of topical iodine medications causing iatrogenic hypothyroidism in patients being treated for other health issues.

Interesting Questions about Thyroid:

How Do Doctors Test For Thyroiditis?

As with any disease, it is important that you watch for the early warning signs of thyroiditis. However, only your doctor can tell for sure whether or not you have the disease. Your doctor may examine:

What About Nodules?

What are hot and cold nodules?

Thyroid nodules do not function like normal thyroid tissue. A thyroid image (scan) done with a radioactive chemical shows the size, shape, and function of the gland and of thyroid nodules. A nodule that takes up more of the radioactive material than the rest of the gland is called a hot nodule.

A nodule that takes up less radioactive material is a cold nodule. Hot nodules are seldom cancerous, but less than 10% of all nodules are hot. Cold nodules may or may not be cancerous. All lumps should be checked by your doctor.

How do doctors test nodules for cancer?

Your doctor can use several tests to find out whether or not a thyroid lump is cancerous.

  • A thyroid image or scan shows the size, shape, and function of the gland. It uses a tiny amount of a radioactive chemical, usually iodine or technetium, which the thyroid absorbs from the blood. A special camera then creates a picture, showing how much iodine was absorbed by each part of the gland.
  • In needle aspiration biopsy, a small needle is inserted into the nodule in an effort to suck out (aspirate) cells. If the nodule is a fluid-filled cyst, the aspiration often removes some or all of the fluid. If the nodule is solid, several small samples are removed for examination under the microscope. In over 90% of all cases, this testing tells the doctor whether the lump is benign or malignant.
  • Ultrasound uses high-pitch sound waves to find out whether a nodule is solid or filled with fluid. About 10% of lumps are fluid-filled cysts, and they are usually not cancerous. Ultrasound may also detect other nodules that are not easily felt by the doctor. The presence of multiple nodules reduces the likelihood of cancer.

How are nodules treated?

Nodules that are thought to be benign are usually observed at regular intervals. Some patients may be advised to take thyroid hormone pills. In certain instances, the nodule may be surgically removed because of continuing growth, pressure symptoms in the neck, or for cosmetic reasons.

Fluid-filled cysts that come back after several aspirations may need to be removed.

If the testing shows a nodule that is, or might be, malignant (cancerous), your doctor will recommend surgery. (You should discuss special situations, such as pregnancy, with your doctor.) The goal of surgery is to remove as much of the cancerous tissue as possible. If the cancer is found in the early stages when it is still confined to the thyroid gland, the surgery is almost always successful. With papillary cancer, patients usually do well after treatment, even if the cancer has spread to the lymph nodes in the neck.

The surgeon starts by removing one lobe of the thyroid. This specimen is tested during surgery (frozen section) to tell the surgeon whether it is benign or malignant. If it is malignant, most or all of the thyroid is removed. If the cancer has spread, lymph nodes in the neck may also have to be removed. In addition, in patients with either papillary or follicular cancer, radioactive iodine therapy may be needed six weeks after surgery to destroy any remaining cancerous tissue.

What happens after surgery?

After surgery, patients must stay in the hospital for one to three days. They may also need to take some time off from work (one to two weeks for a desk job; three to four weeks for physical labor). Most patients do not have any trouble speaking or swallowing, and they report minimal pain after the surgery. In patients with thyroid cancer, a scan may be done approximately six weeks after surgery to detect any residual thyroid tissue that needs to be treated with radioactive iodine.

Patients with thyroid cancer will need to take thyroid hormone their entire lives. Some patients who have had a noncancerous nodule removed will also be advised to take thyroid hormone pills. These may prevent new nodules from forming in the remaining portion of the thyroid gland.

Thyroid Tests

How is thyroid disease discovered?

As with any disease, it is important that you watch for the early warning signs. However, only your doctor can tell for sure whether or not you have thyroid disease. He or she can measure the amount of thyroid hormones in your blood, as well as look at the structure and function of your thyroid gland. If a nodule is found, your doctor can test whether or not it is cancerous.

What are the signs and symptoms of thyroid disease?

When your doctor examines you for thyroid disease, he or she should first ask about your symptoms and then check for physical signs. Your doctor will ask questions about your memory, emotions, or menstrual flow, and then check your heart rate, muscles, skin, and thyroid gland.

Which blood tests will my doctor use?

After a physical examination, your doctor may examine certain hormone levels in your blood. The most common tests check the levels of thyroid hormones (T4 and T3) and thyroid stimulating hormone (TSH). Your doctor may also perform a test with an injection of thyrotropin releasing hormone (TRH). If your doctor suspects Hashimoto’s thyroiditis or Graves’ disease, he or she will probably test you for antithyroid antibodies or thyroid stimulating antibodies.

What does the radioactive iodine uptake show?

Iodine is an important building-block for thyroid hormones. Your doctor may give you a small amount of radioactive iodine and then measure the amount absorbed by the thyroid gland. If the thyroid absorbs a lot of this iodine, you may be hyperthyroid. Low iodine uptake may signal hypothyroidism or thyroiditis.

Why is the structure of my thyroid important?

Examining the structure of your thyroid gland and the surrounding area tells your doctor about a lump (nodule) which may be cancerous or enlargement of the thyroid (goiter).

Which tests look at the structure of my thyroid?

  • A thyroid image (or scan) shows the size, shape, and function of the gland. It uses a radioactive chemical, usually iodine or technetium, which the thyroid absorbs from the blood. A special camera then creates a picture, showing how much chemical was absorbed by each part of the gland. The test shows the size of the thyroid and tells whether lumps are hot (usually benign) or cold (either benign or malignant). The scan is frequently done at the same time as the radioactive iodine uptake.
  • In needle aspiration biopsy, a small needle is inserted into the nodule in an effort to suck out (aspirate) cells. If the nodule is a fluid-filled cyst, the needle often removes some or all of the fluid. If the nodule is solid, several small samples are removed for examination under the microscope. Over 90% of the time, this testing tells the doctor whether the nodule is cancerous or not.
  • Ultrasound uses high-pitch sound waves to find out whether a nodule is solid or filled with fluid. About 10% of nodules are fluid-filled cysts, and they are usually not cancerous. Ultrasound may also detect other nodules that are not easily felt by the doctor. The presence of multiple nodules reduces the likelihood of cancer.

Have more questions? Need more answers? Check our Full Thyroid FAQ

Many cases of drug and medication induced hypothyroidism are reversible as the drugs / medications only interfere with the thyroid’s ability to produce thyroid hormones.  Once these treatments  are discontinued thyroid function often returns to normal.

Surgically induced (post-operative) hypothyroidism – this is often listed as one of the more common non-disease related causes of hypothyroidism.  Surgical treatment (thyroidectomy) for conditions like thyroid cancer, thyroid nodules or Graves’ disease removes either part of the thyroid gland or all of it depending on the extent of the problem.  Iatrogenic hypothyroidism always happens in cases where it is necessary to remove the entire thyroid gland.  If only part of it is removed the thyroid may still retain enough functionality to continue producing sufficient hormone to maintain normal blood levels.  Quite often though it’s the case that the patient is left with impaired thyroid function necessitating life-long thyroid replacement therapy.

Radiation induced hypothyroidism – radioactive iodine may be used as an alternative to surgery to treat Graves’ disease, thyroid cancer or thyroid nodules.  This destroys the thyroid gland, resulting in permanent iatrogenic hypothyroidism.  Other types of upper body cancers and Hodgkin’s disease are treated with radiation therapy, which may result in impaired, or complete loss of, thyroid function.  Again, the result is permanent iatrogenic hypothyroidism.

Iatrogenic Hypothyroidism Symptoms

Regardless of cause, hypothyroidism is hypothyroidism.  It’s caused by insufficient thyroid hormone production.  Therefore, the symptoms of iatrogenic hypothyroidism are identical to those for all other types of hypothyroidism.

Iatrogenic Hypothyroidism Treatment

Many cases of drug induced hypothyroidism will treat themselves once/if the medications and drugs causing the condition are stopped.  It may take a few months however, and during this time the patient may need to be on temporary hormone replacement therapy.  Irreversible iatrogenic hypothyroidism will require the same life-long treatment and life-style management as any other permanent type of hypothyroidism.

Donna Morgan

Donna Morgan

Crank It is where inspiration, aspiration and solution converge to make things ‘happen’. Turn on your life or turn it around and see where it takes you!

Leave a Reply

Your email address will not be published. Required fields are marked *

error: Content is protected !!