Thyroid and You

What is T3 and T4

The thyroid gland produce two major hormones called Triiodothyronine (T3) and Thyroxine (T4). The thyroid gland takes iodine, found in our diet, combines it with an amino acid, tyrosine and converts it into T3 and T4.

  • T3 – Triiodothyronine: Containing three iodine atoms.
  • T4 – Thyroxine: Containing four iodine atoms
T3 Triiodothyronine Image
T4 Thyroxine Image

The Follicular cells are the major cell type in the thyroid gland and are responsible for the production and secretion of the thyroid hormones T3 and T4.

T3 (triiodothyronine): Approximately 20% of T3 is secreted into the bloodstream directly by the thyroid gland. The remaining 80% is produced by the removal of one iodine atom from T4 by a process called deiodination. This process occurs primarily in organs such as the liver and kidneys. T3 is the active form of the thyroid hormone T4 (thyroxine).

T4 (thyroxine): functions as a “storage” hormone. On its own, it is unable to produce energy. Therefore, it must undergo a process known as deiodination in which it loses an atom of iodine to become triiodothyronine (T3).

Both triiodothyronine (T3) and thyroxine (T4) are essential hormones for brain and physical development in infants and for metabolic activity in adults. Thyroid hormones help the brain, heart, liver, muscles, and other organs function properly.

How is T3 and T4 controlled?

The production and release of T3 and T4 is controlled by thyroid stimulating hormone (TSH) secreted by the pituitary gland, which is in turn regulated by thyrotropin-releasing hormone (TRH) secreted by the hypothalamus (a small region of the brain).

Negative Feedback Loop Image
Negative Feedback Loop

This process works as a negative feedback loop. When levels of T3 and T4 decrease below normal, the pituitary gland produces TSH, stimulating the thyroid gland to produce more hormones (T3 and T4). Once the levels rise, the pituitary gland then decreases TSH production.

Hence, this system allows the body to maintain a constant level of T3 and T4 in the body. 

Forms of T3 and T4 hormones.

Most of the T3 and T4 in your body are bound to serum protein such as ( thyroxine-binding globulin (TBG), transthyretin (TTR), albumin, and lipoproteins) and transported throughout the body.

However, a smaller portion of T3 and T4 doesn’t bind to protein is called Free T3 (FT3) & Free T4 (FT4), which circulates through the bloodstream as free or unbound hormones.

T3 exists in two forms in the blood:

  • Bound T3: More than 99.5% of T3 are bound to serum proteins that help transport the hormone through the body.
  • Free or Unbound T3: About 0.5% of T3 doesn’t bind to serum protein is called free T3 and circulates unbound in your blood.

T4 exists in two forms in the blood:

  • Bound T4: More than 99.95% of T4 are bound to serum proteins.
  • Free or Unbound T4: A minimal amount, about 0.02%, of T4 doesn’t bind to serum protein is called free T4 and circulates unbound in your blood.

Why doctors perform T3 and T4 tests

Blood tests for thyroid function such as T3, T4, TSH and others are an important part of diagnosing and treating thyroid disorders. Some conclusions can be drawn from a single test, however a combination of two or more tests are usually needed to check the health of your thyroid.

By comparing the values of different thyroid tests, a doctor can determine whether a person has hypothyroidism  (low thyroid function), hyperthyroidism (overactive thyroid), or an autoimmune thyroid disease such as Graves’ disease or Hashimoto’s thyroiditis.

T3 (triiodothyronine) Test

T3 (triiodothyronine) is a thyroid hormone and the test measures how much is in your blood.

  • Total T3 test: This test simply measures how much of T3 hormone both (bounded and free) is present in your blood. If the level is either abnormally high or abnormally low, it can be an indicator of thyroid disease.
  • Free T3 test: This test just measures free or unbounded T3 present in your blood. This test is often not reliable and therefore not typically helpful.
  • Reverse T3 test: Reverse T3 (RT3) is a biologically inactive protein that is structurally very similar to T3, but the iodine atoms are placed in different locations, which makes it inactive. RT3 is a blood test that not commonly ordered by the doctors.
Reverse T3 Image

What does T3 test results mean?

This single test may not give your doctor any definitive answers about what is wrong. However, abnormal results can help point them in the right direction. If your results show high T3 levels, it may mean you have hyperthyroidism (overactive thyroid). Low T3 levels may mean you have hypothyroidism, a condition in which your body doesn’t make enough thyroid hormone.

However, T3 tests are generally more useful for diagnosing hyperthyroidism than hypothyroidism.

Further, T3 tests are frequently ordered with T4 and TSH (thyroid stimulating hormone) tests, because it can give your doctor a more complete picture of what’s going on.

If you have questions about your results, talk to your health care provider.

T4 (thyroxine) Test

T4 (thyroxine) is a thyroid hormone and the test measures how much is in your blood.

The T4 test measures two key values:

  • Total T4 test: This test measures how much of T4 hormone (both bounded and free) is present in your blood. 
  • Free T4 test: This test just measures free or unbounded T4 present in your blood. A free T4 test is often preferred over a total T4 test.

What does T4 test results mean?

Your results may come in the form of total T4, free T4. High levels of any of these tests (total T4, free T4) may indicate an overactive thyroid, also known as hyperthyroidism. Low levels of any of these tests (total T4, free T4) may indicate an underactive thyroid, also known as hypothyroidism.

Therefore, if your T4 test results are not normal, your health care provider will likely order more thyroid tests to help make a diagnosis. These may include:

  • T3 thyroid hormone tests.
  • A TSH (thyroid stimulating hormone) test.
  • Tests to diagnose Graves’ disease, an autoimmune disease that causes hyperthyroidism.
  • Tests to diagnose Hashimoto’s thyroiditis, an autoimmune disease that causes hypothyroidism.

How do I get ready for T3 and T4 test?

It’s important to tell your doctor about all of the medications you’re currently taking, as some may affect your T3, T4 test results. If your doctor knows about your medications in advance, they can advise you to temporarily stop using them or consider their effect when interpreting your results.
Some medications that can affect your T3, T4 levels include:

  • Thyroid related drugs
  • Steroids
  • Birth control pills or other medications containing hormones, such as androgens and estrogens etc.

In addition, you may also need to fast (not eat or drink) for several hours before the test. Your health care provider will let you know if there are any special instructions to follow.

Procedure for T3, T4 test

A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial (a small glass or plastic bottle).

Blood sample from a vein Image
Blood sample from a vein

You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.

Note: A normal T3 test result doesn’t necessarily mean that your thyroid is functioning perfectly. Measuring your T4 and TSH can help your doctor figure out if you have a thyroid problem despite a normal T3 result.

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What is an Endocrinologist

An endocrinologist is a specially trained doctors who is qualified to diagnose diseases that affect the glands. The conditions that are treated by an endocrinologist are as following:

  • Thyroid diseases
  • Diabetes
  • Hypertension
  • Menopause
  • Over or under production of hormones
  • Lack of growth
  • Metabolic disorders
  • Lipid disorders
  • Cancers of the endocrine glands
  • Osteoporosis

The common diseases and disorders that endocrinologists deal with include diabetes and thyroid disorders.

Endocrinologist Image

An Endocrinologist is a True Specialist

An endocrinologist is a specialist who has thoroughly studied hormonal conditions and knows the best possible treatments, even when conventional treatments do not work well. Unlike a family doctor or general practitioner, an endocrinologist studies hormones and hormonal diseases in depth. Hence, this specialist will be able to provide the best possible treatment. 

What to expect at your first appointment with an endocrinologist

Your endocrinologist is likely to ask you a number of questions. So being prepared before you see him will be of great help to you, as this may save time to go over any particularly important points you feel the need to spend more time on.

Appointment with Endocrinologist Image

He will ask in detail about the symptoms you are experiencing, specifically related to the deficiency or excess of a hormone you may have.

Your doctor may ask:

  • What are your symptoms, and when did you first notice them?
  • How have your symptoms changed over time?
  • Has your appearance changed, including your weight or the amount of your body hair?
  • Have any of your family members been diagnosed with thyroid disease, hormonal or autoimmune conditions?
  • Are you currently being treated or have you recently been treated for any other medical conditions?
  • Have you recently had a baby?
  • Have you lost interest in sex? If you’re a woman, has your menstrual cycle changed?
  • Have you had any recent head injuries or have you had neurosurgery?

Further, your examination will depend on the type of problem you have. Your endocrinologist will look for signs of a disease as well as complications of the disease and treatments.

An Endocrinologist Works with Your Primary Care Doctor

Visiting an endocrinologist does not mean you will never see your primary care doctor again. Going to an endocrinologist when struggling with a hormonal condition gives you another set of eyes to ensure your health is as good as it can be.

Remember, your goal when facing a hormonal disease diagnosis should be to take care of your disease as best as possible. This is often done with the support of an endocrinologist. 

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Antithyroid Medications

Antithyroid medications are used to treat an overactive thyroid gland (also know as hyperthyroidism). When the thyroid gland is overactive, it makes too much thyroxine (also known as T4). The extra thyroxine can accelerate the metabolism rate of your body. As a result, it can cause weight loss and irregular heart activity.

Antithyroid Medication Image

Therefore, antithyroid medications (which includes methimazole and propylithiouracil) are used to reduce the amount of hormone (T4) released by the thyroid gland. These drugs does not affect the thyroxine which is already made, but reduce the further production. Therefore, it may take four to eight weeks of treatment for your thyroxine level to come down to normal.

Antithyroid Drugs during pregnancy

If you take antithyroid drugs, you should discuss your treatment with your doctor before becoming pregnant:

  • Methimazole: Using methimazole during pregnancy could harm the unborn baby. Tell your doctor if you are pregnant or if you become pregnant while using this medicine.

Methimazole can pass into breast milk and may harm a nursing baby. Ask your doctor about any risk.

  • Propylthiouracil: Do not use propylthiouracil if you are pregnant. Tell your doctor right away, if you become pregnant. This medicine can harm an unborn baby, or cause serious liver problems or death of the baby or the mother. You may need to use another medication during late pregnancy.

It may not be safe to breast-feed while using propylthiouracil. Ask your doctor about any risk.

Side Effects of Antithyroid medications?

You may require careful monitoring to get the right levels of these medicines for you. However, when taking an antithyroid medicine, if you develop any of the side-effects (listed below) or any other signs of infection, you must stop the medicine and report this to your doctor immediately.

  • Rash
  • Mild stomach upset
  • Headache
  • Painful joints

The above side-effects are usually not serious and often go, even if you continue with the medication.

But in rare cases, antithyroid medicine can cause a serious side-effect on the blood-making cells. This can drastically reduce the number of blood cells in your body, including the cells that fight off infection and those that help to stop bleeding.

There’s also the risk of liver damage. Therefore, see your doctor right away if you develop following symptoms, while taking these drugs.

  • A sore throat.
  • Mouth ulcers.
  • Unexplained bruising or bleeding.
  • Rash
  • Fever
  • Itching
  • Jaundice (yellowing of the skin and eyes)
  • Any other signs of infection.
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Thyroid Cancer

Thyroid cancer is a disease in which malignant (cancer) cells form in the tissues of the thyroid gland. The malignant cells begin multiplying in your thyroid and, once there are enough of them, they form a tumor. It can occur in any age group, although it is most common after age 30. Females are more likely to have thyroid cancer.

Thyroid Cancer Image

If it’s caught early, then thyroid cancer is one of the most treatable forms of cancer.

Types of Thyroid Cancer

Thyroid cancer is classified into types based on the kinds of cancerous cells found in the tumor. Your type is determined, when a sample of tissue from your cancer is examined under a microscope.

There are 4 main types of it, and some are more common than others.

Papillary thyroid cancer: It is the most common type, making up about 70% to 80% of all thyroid cancers. Papillary thyroid cancer can occur at any age. It tends to grow slowly and often spreads to lymph nodes in the neck. Even when this cancer have spread to the lymph nodes, it can often be treated successfully and are rarely fatal.

Follicular thyroid cancer. Follicular cancer can spread into your lymph nodes and is also more likely to spread to distant organs, particularly the lungs and bones.

Medullary thyroid cancer (MTC) : It begins in thyroid cells called C cells, which produce the hormone calcitonin, a hormone that helps control the amount of calcium in blood. Elevated levels of calcitonin in the blood can indicate medullary thyroid cancer at a very early stage.

This type of cancer is more difficult to find and treat, There are 2 types of MTC:

  • Sporadic MTC: It accounts for about 8 out of 10 cases of MTC, is not inherited (meaning it does not run in families). It occurs mostly in older adults.
  • Familial MTC: It is inherited (runs in families). These cancers often develop during childhood or early adulthood and can spread early.

Anaplastic thyroid cancer: It is the most advanced and aggressive thyroid cancer and the least likely to respond to treatment. It is very rare and is found in less than 2% of patients with thyroid cancer. This cancer often spreads quickly into the neck and to other parts of the body, and is very hard to treat.

Other rare types: Other very rare types of cancer that start in the thyroid includes:

  • Thyroid lymphoma: which begins in the immune system cells of the thyroid.
  • Thyroid sarcoma: which begins in the connective tissue cells of the thyroid.


Thyroid cancer may not cause early signs or symptoms. That’s because there are very few symptoms in the beginning. Signs or symptoms may occur as the tumor gets bigger. Check with your doctor if you have any of the following:

  • A lump (nodule) in the neck.
  • Trouble breathing.
  • Pain when swallowing.
  • Hoarseness.

What cause thyroid cancer?

It is more common in people who have a history of exposure to high doses of radiation, have a family history of thyroid cancer, and are older than 40 years of age. However, for most patients, there is no specific reason why they get it.

Diagnosing Thyroid Cancer

Thyroid cancer may be diagnosed after a person goes to a doctor because of symptoms, or it might be found during a routine physical exam or other tests. If there is a reason to suspect you might have thyroid cancer, your doctor will use one or more tests to confirm the diagnosis.

Physical Exam: Your doctor will examine your neck to feel for physical changes in your thyroid, such as thyroid nodules. He or she may also ask about your risk factors, such as past exposure to radiation and a family history of thyroid tumors.

Blood tests: Blood tests are not used to find thyroid cancer. But they can help show if your thyroid is working normally, which may help the doctor decide what other tests may be needed. They can also be used to monitor certain cancers.

Calcitonin level in the blood: Calcitonin is a hormone that helps control how the body uses calcium. It is made by C cells in the thyroid, the cells that can develop into medullary thyroid cancer (MTC). If MTC is suspected or if you have a family history of the disease, blood tests of calcitonin levels can help look for MTC. Because calcitonin can affect blood calcium levels, these may be checked as well.

Ultrasound imaging: Ultrasound uses high-frequency sound waves to create pictures of body structures. To create an image of the thyroid, the ultrasound transducer is placed on your lower neck. The image of your thyroid and any nodules, even those you can’t feel, will show up on a computer screen.

This test can help determine if a lump is filled with fluid or if it’s solid. A solid one is more likely to have cancerous cells, but you’ll still need more tests to find out. The ultrasound will also show the size and number of nodules on your thyroid.

Thyroid Biopsy: The actual diagnosis of thyroid cancer is made with a biopsy, in which cells from the suspicious area are removed and looked in the laboratory for cancer cells.

If your doctor thinks a biopsy is needed, he/she will do (Fine needle aspiration (FNA)) biopsy, in which a small, thin needle is used to take a little sample from the lump, and maybe other places around it. This type of biopsy can sometimes be done in your doctor’s office or clinic. You won’t need any recovery time afterward.

Fine Needle Aspiration Biopsy Image
Fine Needle Aspiration Biopsy

After he gets the sample, the doctor will send the sample to a lab for testing.

Genetic testing: Based on your family history, your doctor might order genetic testing to find out if you have any genes that make you more likely to get cancer. It can also show genetic changes that could be a sign of certain types of thyroid cancer.

Radioiodine scan: This can be used to help determine if someone with a lump in the neck might have thyroid cancer. For this test, a small amount of radioactive iodine is swallowed (usually as a pill) or injected into a vein. Over time, the iodine is absorbed by the thyroid gland (or thyroid cells anywhere in the body). A special camera is used several hours later to see where the radioactivity is.

CT Scan (Computed tomography): Computed tomography, commonly called a CT scan or CAT scan, uses special X-rays to give your doctor a look inside of your body. It can show the size and location of thyroid cancer and whether it has spread to other parts of your body.

MRI Scan (Magnetic resonance imaging): A MRI can be used to look for cancer in the thyroid, or cancer that has spread to nearby or distant parts of the body. MRI can provide very detailed images of soft tissues such as the thyroid gland.

PET Scan (Positron emission tomography): This test uses small amounts of radioactive material, called radiotracers, a special camera, and a computer to look at your organs and tissue. A PET scan looks at changes on the cellular level. It may be able to detect the cancer in a very early state and check for cancer spread.

Treatment of thyroid cancer

Your thyroid cancer treatment depend on the type and stage of your thyroid cancer. It also depends on your age, general health, and other things that are unique to you. The treatment options for thyroid cancer might include:

Surgery: Surgery is the main treatment, in nearly every case of thyroid cancer. If thyroid cancer is diagnosed by biopsy, surgery to remove the tumor and all or part of the remaining thyroid gland is usually recommended. Operations used to treat thyroid cancer include:

  • Lobectomy (Removing a portion of the thyroid gland): During this operation, the surgeon removes half of the thyroid. It might be recommended if you have a slow-growing thyroid cancer in one part of the thyroid and no suspicious nodules in other areas of the thyroid.
  • Thyroidectomy (Removing all or most of the thyroid gland): It is a surgery to remove the thyroid gland. If the entire thyroid gland is removed, it is called a total thyroidectomy. Sometimes the surgeon may not be able to remove the entire thyroid. If nearly all of the gland is removed, it is called a near-total thyroidectomy.
  • Lymph node removal: If cancer has spread to nearby lymph nodes in the neck, these will be removed at the same time surgery is done on the thyroid. 

Complications are less likely to happen when your operation is done by an experienced thyroid surgeon. However, thyroid surgery still carries a risk of bleeding and infection. Damage to your parathyroid glands also can occur during surgery, which can lead to low calcium levels in your body.

There’s also a risk that the nerves connected to your vocal cords might not work normally after surgery, which can cause vocal cord paralysis, hoarseness, voice changes or difficulty breathing.

Radioactive Iodine Therapy: The thyroid gland and most thyroid cancers absorb iodine. Radioactive iodine (RAI) ablation is used to destroy any thyroid tissue that’s left after a thyroidectomy. The Radioactive Iodine collects mainly in thyroid cells, where the radiation destroys the thyroid gland and any other thyroid cells (including cancer cells), with little effect on the rest of your body.

The level of radiation in this treatment is far higher than what is used in a radioiodine scan.

Side effects of RAI treatment may include:

  • Dry mouth
  • Nausea and vomiting
  • Neck tenderness and swelling
  • Taste changes

Most of the radioactive iodine leaves your body in your urine in the first few days after treatment. You will be given instructions on how to protect others from radiation exposure and how long you need to take these precautions. These instructions may vary slightly by treatment center. Be sure you understand the instructions before you leave the hospital.

External beam radiation therapy: Radiation therapy can also be given externally using a machine that aims high-energy beams, at precise points on your body to destroy cancer cells or slow their growth. During treatment, you lie still on a table while a machine moves around you.

External beam radiation therapy is often used for cancers that continues to grow even after radioactive iodine treatment and have spread beyond the thyroid. Radiation therapy may also be recommended after surgery if there’s an increased risk that your cancer will recur.

Chemotherapy (chemo): Chemotherapy uses anti-cancer drugs that are injected into a vein or are taken by mouth. Chemotherapy is systemic therapy, which means that the drug enters the bloodstream and travels throughout the body to reach and kill cancer cells.

Chemo isn’t commonly used in the treatment of thyroid cancer, but it’s sometimes recommended for people with anaplastic thyroid cancer. Chemotherapy may be combined with external beam radiation therapy.

Chemotherapy has side effects, but your doctor will help you to manage them.

Targeted drug therapy: It is a newer treatment that targets only certain parts of cancer cells, to slow or stop growth. This is normally taken in pill form. It’s typically used in advanced thyroid cancer. Usually, there are fewer side effects than with chemotherapy.

Follow-up care

Follow-up is needed to check for cancer recurrence or spread, as well as possible side effects of certain treatments. It’s important for all thyroid cancer survivors to let their health care team know about any new symptoms or problems, because they could be caused by the cancer coming back or by a new disease or second cancer.

Most people do very well after treatment, but follow-up care is very important since most thyroid cancers grow slowly and can recur even 10 to 20 years after initial treatment.

Thyroid Cancer Prognosis

Overall, the prognosis of differentiated thyroid cancer is excellent, especially for patients younger than 45 years of age and those with small cancers. Patients with papillary thyroid cancer, who have a primary tumor that is limited to the thyroid gland have an excellent outlook. For patients older than 45 years of age, or those with larger or more aggressive tumors, the prognosis remains very good, but the risk of cancer recurrence is higher.

The prognosis may not be quite as good in patients whose cancer is more advanced and cannot be completely removed with surgery or destroyed with radioactive iodine treatment. However, these patients often are able to live a long time and feel well, despite the fact that they continue to live with cancer. 

Furthermore, it is important to talk to your doctor about your individual profile of cancer and expected prognosis. It will be necessary to have lifelong monitoring, even after successful treatment.

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Thyroid Nodule

The term thyroid nodule refers to an abnormal growth of thyroid cells that forms a lump within the thyroid gland. It can be solid or filled with fluid. You can have a single nodule or a cluster of nodules in thyroid gland. Most thyroid nodules aren’t serious and don’t cause symptoms. Only a small percentage of thyroid nodules are cancerous.

A thyroid nodule can occur in any part of the gland. Some nodules can be felt quite easily. Others can be hidden deep in the thyroid tissue or located very low in the gland, where they are difficult to feel. You often won’t know you have a thyroid nodule until your doctor discovers it during a routine medical exam.

Thyroid Nodule Image
Thyroid Nodule Image

Types of Thyroid Nodules

There are several different types of thyroid nodules.

Toxic Nodules: This occurs when thyroid nodules, makes the thyroid gland overactive. In other words, thyroid gland starts producing excess thyroid hormones. It is known as toxic nodules. It may also lead to hyperthyroidism. In which the body’s metabolism speeds up. Toxic nodules may slowly become very large and press on surrounding structures in the neck or upper chest.

Toxic nodules are almost always benign (noncancerous), but they may require treatment to address hyperthyroidism.

Multinodular Goiter: When more than one nodules grow on thyroid gland the condition is called a multinodular goiter, or enlarged thyroid. Furthermore, Multinodular goiters can be either a toxic multinodular goiter (i.e. makes too much thyroid hormone and causes hyperthyroidism or non-toxic (i.e. does not make too much thyroid hormone and causes hypothyroidism).

It is associated with a higher risk of thyroid cancer. Up to 20 percent of people with multinodular goiters will also develop thyroid cancer. If you do have a multinodular goiter, your doctor will most likely screen you for thyroid cancer as well.

Thyroid Cyst: When thyroid nodules contain fluid, they are called cystic nodules. These can be completely filled with fluid known as simple cysts, or filled with partly solid and partly fluid known as complex cysts. Cysts are usually noncancerous, but they occasionally contain cancerous solid components.

Hot and Cold Nodules: Nodules detected by thyroid scans are classified as cold, hot, or warm. If a nodule is composed of cells that do not make thyroid hormone, then it is “cold”. If a nodule that is producing too much hormone is called “hot.”

85% of thyroid nodules are cold, 10% are warm, and 5% are hot. Remember that 85% of cold nodules are benign (noncancerous), 90% of warm nodules are benign, and 95% of hot nodules are benign.

Although thyroid scanning cannot truly differentiate benign or malignant nodules. Therefore, the evaluation of a thyroid nodule should always include history and examination by a physician. Remember, a biopsy is the only way to tell for sure that a nodule is benign or malignant.

Symptoms of a thyroid nodule?

Most thyroid nodules do not cause symptoms. Often, thyroid nodules are discovered incidentally during other routine physical examination. Occasionally, patients themselves find thyroid nodules by noticing a lump in their neck while looking in a mirror, buttoning their collar, or fastening a necklace. 

However, if the thyroid nodule gets large enough, you may develop following symptoms:

  • An enlarged thyroid gland, known as a goiter.
  • A few people with thyroid nodules complain of pain at the site of the nodule that can travel to the ear or jaw.
  • Breathing difficulties
  • Swallowing difficulties
  • Rarely, a person with a thyroid nodule may complain of hoarseness or difficulty speaking because of compression of the voice box.

Furthermore, if your thyroid nodule is producing excess thyroid hormones, you may also develop symptoms of hyperthyroidism, such as:

  • Unexplained weight loss
  • Increased sweating
  • muscle weakness
  • difficulty sleeping
  • Tremor
  • Rapid or irregular heartbeat

If production of your thyroid hormones is too low due to thyroid nodule, you may also develop symptoms of hypothyroidism, such as:

  • Weight Gain
  • Dry Skin
  • Puffy Face
  • Cold Sensitivity
  • Tiredness
  • Depression

Very rarely, nodules may cause pain or discomfort. But the most common of these symptoms is a lump in the neck followed by a sense of mass while swallowing.

What may cause thyroid nodules?

It’s not always clear why a person gets thyroid nodules. Several medical conditions can cause them to form. They include:

  • Genetics
  • Iodine deficiency
  • Hashimoto’s disease, an autoimmune disease that leads to hypothyroidism.
  • Thyroiditis or chronic inflammation of the thyroid.

Furthermore, cancer is the biggest concern when nodules form. Fortunately, cancer is very rare. Over 90% of such nodules are benign (noncancerous), but still, it is important to see a doctor if you think you have a nodule.

In addition, the risk for thyroid nodules is higher in women than men. Incidence increases with age, and is greater in people exposed to radiation from medical treatments

How are thyroid nodules diagnosed?

Thyroid nodules usually are discovered by the health care professional during routine physical examination of the neck. Once a nodule is discovered, a physician will use one or more of the following tests to diagnose and assess your nodule:

Ultrasonography: A physician may order an ultrasound examination of the thyroid to:

  • Detect nodules that are not easily felt.
  • Determine the number of nodules and their sizes.
  • Determine if a nodule is solid or cystic.

Despite its value, the ultrasound cannot determine whether a nodule is benign or cancerous.

Thyroid Fine Needle Aspiration Biopsy (FNA or FNAB): For a fine needle biopsy, your doctor will use a very thin needle to withdraw cells from the thyroid nodule. Ordinarily, several samples will be taken from different parts of the nodule to give your doctor the best chance of finding cancerous cells if they are present.

The cells are then examined under a microscope by a pathologist to check if nodule is benign (noncancerous), malignant (cancerous) or suspicious for malignancy.

Blood tests: Your doctor may take a blood sample to measure levels of T3 and T4—the thyroid hormones, and thyroid-stimulating hormone (TSH).

  • Elevated levels of the thyroid hormones (T4 & T3) and low level of TSH (thyroid stimulating hormone) suggests hyperthyroidism.
  • Abnormally low level of the thyroid hormones (T4 & T3) and elevated level TSH (thyroid stimulating hormone) suggests hypothyroidism.
  • A antibodies test detects the antibodies against TPO (Thyroid Peroxidase) in the blood. The presence of TPO antibodies in your blood suggests that the cause of thyroid disease is an autoimmune disorder, such as Hashimoto’s disease or Graves’ disease.

Molecular Diagnostics: It examines the genes in the DNA of thyroid nodules. Therefore, these tests can provide helpful information about whether cancer may be present or absent.

These tests are particularly helpful when the specimen evaluated by the pathologist is indeterminate. These specialized tests are done on samples, which is obtained during the normal biopsy process. These are currently available only at highly specialized medical centers, however, their availability is increasing rapidly.

Thyroid Scans: Your doctor may recommend a thyroid scan to help evaluate thyroid nodules. During this test, an isotope of radioactive iodine is injected into a vein in your arm. You then lie on a table while a special camera produces an image of your thyroid on a computer screen.

Nodules that produce excess thyroid hormone — called hot nodules — show up on the scan because they take up more of the isotope than normal thyroid tissue does. Hot nodules are almost always noncancerous.

In some cases, nodules that take up less of the isotope — called cold nodules — are cancerous. However, a thyroid scan can’t distinguish between cold nodules that are cancerous and those that aren’t cancerous.

How are thyroid nodules treated?

Your treatment options will depend on the size and type of thyroid nodule you have.

Observation: If a thyroid nodule is benign (noncancerous) and small, the usual treatment is “watchful waiting.” This is not a form of active treatment but rather an observation period. Patients treated this way should be checked by their doctor every 3 months to monitor the growth of the nodule. As long as the nodule does not grow, there’s usually no need to worry. 

Radioactive iodine treatment: Nodules that make too much thyroid hormone may be treated with radioiodine. It’s radioactive iodine that can be taken in a pill or liquid form. It helps reduce the size of the thyroid nodule without harming other tissue.

Thyroid hormone therapy: If your thyroid function test finds your gland isn’t producing enough thyroid hormone, your doctor may recommend thyroid hormone therapy (Synthetic levothyroxine).

Surgery: If a nodule is cancerous or grows despite hormone pill treatment, surgery to remove the nodule may be needed. Almost all thyroid nodules that are malignant (cancerous) are treated by surgery. A noncancerous nodule may sometimes require surgery if it’s so large that it makes it hard to breathe or swallow.

Can thyroid nodules be prevented?

There’s no way to prevent the development of a thyroid nodule. However, most people who have thyroid nodules lead a normal life. You might need to check in with your doctor more often, but there usually are no complications.

Furthermore, if your thyroid nodules have symptom of thyroid cancer, you may need surgery. During the surgery, the doctor will remove most (if not all) of your thyroid. After the surgery, you’ll take daily thyroid replacement hormones for the rest of your life.

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