If your thyroid gland is on the fritz, it can make you feel sluggish, make your hair fall out, keep you from being able to lose weight and cause your skin to be dry.
What is the thyroid gland?
The thyroid gland is a small gland that lives at the base of the neck. It is composed of two lobes that are on either side of the trachea and a connecting bridge of tissue that connects the two called the isthmus. The tissue of the thyroid is filled with small lobules wrapped in tissue to hold them together. The lobules are filled with small sacs which store drops of thyroid hormone.
What is the function of the thyroid gland?
The thyroid gland is responsible for producing three hormones:
- T3 (triiodothyronine)
- T4 (tetraiodothyronine or thyroxine)
These hormones influence many functions in the body.
- Metabolism – The thyroid hormone regulates the way that your body uses energy.
- Body temperature – Small changes in blood pressure can affect how proteins and enzymes in the bloodstream function.
- Heart rate and blood pressure – Thyroid hormones affect how the heart muscles contract and how the muscles in the arteries contract and relax.
- Food movement through the digestive tract – The exact mechanism is not well understood, but both too much or too little thyroid hormone can affect digestion and liver function.
- Brain development – Thyroid hormone is vitally important in the development of the brain both before birth and during infancy.
- Muscle contraction
- Skin and bone maintenance
How is thyroid function tested?
If you’re concerned about thyroid function, or if your symptoms are suspicious for thyroid disease, your healthcare provider may choose to order bloodwork or other testing. The most commonly ordered tests of thyroid function include thyroid stimulating hormone (TSH), total or free T4 levels, and total or free T3 levels. Sometimes additional bloodwork or imaging is necessary to help with diagnosis.
Symptoms of thyroid disease
Thyroid disease can have several symptoms depending on the severity of the disease as well as the nature of the disease itself.
In hyperthyroid conditions, the thyroid hormone levels are too high. This can cause many symptoms including palpitations, nervousness, anxiety, hyperactivity, mood swings, insomnia, fatigue, sensitivity to heat, weakness, itchiness, diarrhea, and more.
In hypothyroidism, the thyroid hormones are too low. Symptoms associated with low thyroid hormone levels include fatigue, weight gain, cold intolerance, joint and muscle pain, dry skin or hair, hair loss, heavy periods, irregular periods, difficulty getting or staying pregnant, low heart rate, and depression.
Euthyroid Condition Symptoms
In some cases, the problem with the thyroid is not related to its function. Thyroid blood tests can be normal. This is called euthyroid. Swelling of the thyroid gland can cause a lump on the side of the neck called a goiter. It can also present with lumps or nodules. Sometimes swelling can get so severe that it can affect your voice, breathing, or swallowing.
Graves’ disease is one of the more common types of hyperthyroidism. Graves’ disease is an autoimmune disease where the body creates antibodies that attack the thyroid gland stimulating the receptor in the thyroid that senses thyroid stimulating hormone. This causes the thyroid gland to over-produce thyroid hormone. In addition to the symptoms of hyperthyroidism listed above, graves’ patients may experience swelling of the neck (goiter), swelling of the shins (pretibial myxedema), and swelling of the eyes (exophthalmos). If you have exophthalmos, you may also experience increased eye sensitivity, eye irritation, blurred vision, double vision, or changes in your ability to perceive color. In rare cases, graves disease can cause changes in the color of the skin and clubbing of the fingers with swelling in the hands and feet.
Graves’ disease is more common in people with a family history of thyroid disease and those with other disorders such as vitiligo (a condition that causes loss of pigment in the skin), autoimmune gastritis (where the body attacks the gut), type 1 diabetes, or rheumatoid arthritis as well as those people who use nicotine-containing products. Graves’ patients are at an increased risk of atrial fibrillation (an irregular heart rate), stroke, heart problems, osteoporosis, difficulty with fertility and pregnancy, and eye problems.
Graves’ disease is diagnosed with lab testing including thyroid antibody levels and thyroid-stimulating immunoglobulin. Other testing including a radioactive iodine uptake test, or a thyroid scan may be used for evaluation.
Graves’ disease can be treated with medication to treat the symptoms such as the rapid heart rate or anti-thyroid medications to reduce the thyroid hormone levels. Care must be taken if you are pregnant with graves’ disease as some medications are not safe in pregnancy. If medications are not successful in improving Graves’ disease symptoms, sometimes radioactive iodine is used to ablate or destroy the thyroid tissue to stop excessive thyroid hormone production. With this treatment, you become hypothyroid and will likely need thyroid hormone replacement for the rest of your life. Sometimes, thyroid surgery is necessary to treat the disease.
Hashimoto’s disease is also known as chronic lymphocytic thyroiditis and is another type of autoimmune thyroid condition. Hashimoto’s is the most common cause of hypothyroidism in the United States and frequently runs in families. It is more common in women and as people age, but anyone can get Hashimoto’s.
Hashimoto’s disease can cause symptoms of hyperthyroidism or hypothyroidism. Early in the disease process, the inflammation of the thyroid gland can cause hyperthyroidism, but as the gland is destroyed by the antibodies, you become hypothyroid. Other symptoms include swelling of the thyroid gland, menstrual problems, and difficulty getting or staying pregnant. The condition is usually not painful, but in rare cases, the thyroid gland can be painful.
Hashimoto’s disease is generally diagnosed with labs. Usually, thyroid function and thyroid antibodies are evaluated. Sometimes additional labs or a radioactive iodine uptake study are done to confirm the diagnosis.
Hashimoto’s is generally treated with thyroid replacement medications if hypothyroidism is present. If the thyroid hormone levels are in the normal range, then sometimes just monitoring symptoms is sufficient, and additional treatment is not necessary.
Thyroiditis is a general term that means inflammation of the thyroid gland. It can be painful or painless and can present with hyperthyroidism, hypothyroidism, or euthyroid. We’ve already discussed Hashimoto’s which is one of the conditions that is associated with thyroiditis. These conditions are usually separated into painful or painless conditions.
Painful thyroiditis conditions include subacute granulomatous (usually caused by a viral infection), suppurative (due to a non-viral infection), or destructive (typically associated with radiation or trauma).
Nonpainful thyroiditis is more common. Several conditions are associated with nonpainful thyroiditis. Hashimoto’s is the most common, and we’ve previously discussed this. Postpartum thyroiditis, subacute lymphocytic, and drug-induced are the other forms of nonpainful thyroiditis seen.
Thyroiditis is usually treated based on the type and cause. Thyroid replacement is used if indicated by labwork.
Congenital hypothyroidism is present at birth and is usually found on newborn screening tests. Congenital hypothyroidism is the most common preventable cause of intellectual disability. This condition may persist throughout life or can resolve as the child ages. This condition is usually asymptomatic at birth because the mother's thyroid hormone crosses the placenta to the baby. Within the first few weeks, symptoms such as lethargy, decreased muscle tone, large fontanels (soft spots), constipation, difficulty feeding, jaundice, hoarse cry, or difficulty with temperature may develop. Symptoms can progress to puffy eyelids, large tongue, coarse hair, skin changes, abdominal distension, and additional symptoms.
If the initial screening tests are suggestive of congenital hypothyroidism, additional laboratory testing may be indicated, but usually imaging isn’t required. The condition is generally treated with thyroid replacement medications.
Goiter is a term used to describe swelling in the neck due to an enlarged thyroid gland. The most common cause of goiter in the world is low dietary iodine. In the United States, salt is frequently supplemented with iodine so dietary deficiency is uncommon and goiters are usually associated with thyroid nodules, thyroiditis, or thyroid cancer.
Goiter may present with hyperthyroidism, hypothyroidism, or euthyroid. Treatment of goiter includes observation, medication, surgery, or radiofrequency ablation of the thyroid gland.
Thyroid nodules can be cystic (fluid-filled) or solid. They can be hot (thyroid hormone-producing) or cold (non thyroid hormone-producing). They may have no symptoms or may be associated with hyperthyroidism or hypothyroidism symptoms. They can be evaluated with a radioactive iodine uptake scan, an ultrasound, and lab work. Sometimes, a biopsy may be necessary to rule out cancer.
Thyroid nodules can be monitored if they are non-cancerous. If they are causing hyperthyroidism or hypothyroidism, this can be treated with one of the previously mentioned options.
Thyroid cancer is becoming increasingly common. There are several forms of thyroid cancer based on the types of cells in the thyroid gland that the cancer derives from. Papillary and follicular thyroid cancer are the most common forms. If thyroid cancer is detected on a biopsy, then treatment may be necessary. Generally, surgery is the first step in the treatment of thyroid cancer. This may be followed by radioactive iodine therapy to destroy any remaining thyroid tissue. After radioactive iodine therapy, thyroid hormone replacement is usually necessary. If thyroid cancer spreads beyond the thyroid gland, other treatments including chemotherapy or radiation may be necessary under the guidance of an oncologist (cancer specialist).
Thyroid disease can affect many aspects of your life. The best way to approach your health is to be proactive and discuss your symptoms with your healthcare provider. If your healthcare provider has recommended medication, consider visiting us at WellRx to help find the best prices in your area. WellRx has been helping consumers save on their prescriptions for 25 years.
Dr. Foglesong Stabile is a board-certified Family Physician who enjoys full scope Family Medicine, including obstetrics, women’s health, and endoscopy, as well as caring for children and adults of all ages. She also teaches the family medicine clerkship for Pacific Northwest University of Health Sciences.