Understanding Hypothyroidism: Causes, Risks, and Treatment Options

Written By Adama Diarra, DO, FACP

What is Hypothyroidism?

Hypothyroidism is a condition in which the thyroid gland, located at the base of your neck, doesn’t produce enough thyroid hormones. These hormones are crucial for regulating your metabolism, which affects how your body uses energy. When the thyroid doesn’t produce enough hormones, many bodily functions slow down, leading to symptoms such as fatigue, weight gain, dry skin, hair thinning, constipation, and feeling cold.

Thyroid hormones, mainly thyroxine (T4) and triiodothyronine (T3), play a key role in regulating everything from your heart rate to body temperature. A lack of these hormones can have widespread effects on your body, which is why early detection and treatment are so important.

Types of Hypothyroidism

There are different types of hypothyroidism, each with its own causes and risk factors.

1. Hashimoto’s Disease (Autoimmune Hypothyroidism)

Hashimoto's thyroiditis is the most common cause of hypothyroidism. It’s an autoimmune condition in which the immune system mistakenly attacks the thyroid gland, causing inflammation and reducing its ability to produce hormones. Over time, the thyroid becomes damaged, leading to hypothyroidism.

  • Risk factors: Hashimoto’s disease is more common in women, particularly those over 50. A family history of autoimmune conditions also increases your risk, as does having other autoimmune diseases like type 1 diabetes or rheumatoid arthritis.

2. Radiation-Induced Hypothyroidism

Exposure to radiation, either from cancer treatments targeting the head or neck or from radioactive iodine treatment for hyperthyroidism, can damage the thyroid gland, leading to hypothyroidism.

  • Risk factors: Those who undergo radiation therapy for cancers of the head, neck, or upper chest (such as Hodgkin’s lymphoma), or receive radioactive iodine for hyperthyroidism, are at risk of developing hypothyroidism.

3. Surgical Hypothyroidism

Surgical removal of part or all of the thyroid gland (thyroidectomy) to treat thyroid cancer, nodules, or goiters can result in hypothyroidism if too much of the gland is removed and not enough thyroid hormone is produced.

  • Risk factors: People who have had surgery to remove part or all of their thyroid gland are at risk of developing hypothyroidism.

4. Congenital Hypothyroidism

Some individuals are born with an underactive thyroid, a condition known as congenital hypothyroidism. It occurs when the thyroid gland doesn’t develop properly before birth.

  • Risk factors: This type of hypothyroidism is usually detected shortly after birth through routine newborn screening.

5. Drug-Induced Hypothyroidism

Certain medications, such as amiodarone (used to treat heart arrhythmias) or lithium (used to treat bipolar disorder), can interfere with thyroid function and lead to hypothyroidism.

  • Risk factors: Individuals taking medications like amiodarone or lithium are at higher risk for hypothyroidism.

Complications of Untreated Hypothyroidism

If left untreated, hypothyroidism can lead to serious health complications. The slower metabolism caused by low thyroid hormone levels affects many organs and systems in the body.

1. Heart Disease

Low levels of thyroid hormones can increase LDL cholesterol (bad cholesterol), leading to a higher risk of heart disease and heart failure. Over time, untreated hypothyroidism can cause the heart to pump less efficiently, leading to complications like cardiomyopathy (weakened heart muscle).

2. Infertility and Pregnancy Complications

Women with untreated hypothyroidism may have difficulty becoming pregnant due to irregular ovulation. Hypothyroidism during pregnancy can lead to complications, including miscarriage, preterm birth, and developmental issues in the baby.

3. Myxedema Coma

In severe cases, untreated hypothyroidism can lead to a rare but life-threatening condition known as myxedema coma. This condition causes extreme drowsiness, slowed breathing, and hypothermia. It is a medical emergency that requires immediate treatment.

4. Mental Health

Untreated hypothyroidism can lead to depression, memory problems, and slowed cognitive function. In some cases, these symptoms may be mistaken for other mental health disorders, delaying proper treatment.

Early Detection and Diagnosis

Early detection of hypothyroidism is key to preventing complications. Routine screenings or annual checkups that include blood tests to measure thyroid-stimulating hormone (TSH) levels can help identify hypothyroidism before symptoms worsen. High TSH levels indicate that the thyroid gland isn’t producing enough thyroid hormones, prompting the body to produce more TSH to stimulate the thyroid.

Individuals at higher risk for hypothyroidism, such as those with a family history or autoimmune conditions, should consider regular thyroid screenings as part of their annual health checkups.

How to Treat Hypothyroidism

Once hypothyroidism is diagnosed, the goal of treatment is to restore normal thyroid hormone levels in the body. Fortunately, hypothyroidism is generally easy to treat and manage with medication, though it typically requires lifelong monitoring and adjustments.

Lifestyle Interventions

Unlike some conditions, there are no specific lifestyle changes or dietary interventions that can cure hypothyroidism. However, maintaining a healthy lifestyle can help manage the symptoms:

  • Eat a balanced diet: A diet rich in fruits, vegetables, lean proteins, and whole grains supports overall health, though it won’t directly treat hypothyroidism.

  • Exercise regularly: Exercise can help manage weight gain and boost energy, both of which are common issues in hypothyroidism.

  • Adequate iodine intake: Iodine is essential for thyroid function, but in countries like the U.S., where iodine deficiency is rare, additional iodine supplementation is generally not necessary. Too much iodine can actually worsen thyroid problems.

While these interventions can support overall health, medication is the primary treatment for hypothyroidism.

Medications for Hypothyroidism

Several medications are available in the U.S. to treat hypothyroidism. The primary goal is to replace the missing thyroid hormones and restore normal thyroid function.

  1. Levothyroxine (Synthroid, Levoxyl, Euthyrox)

    • How it works: Levothyroxine is a synthetic bioidentical human form of thyroxine (T4), the hormone that your thyroid normally produces. The term bioidentical means it has all the same component that your thyroid hormone has. It’s the most commonly prescribed medication for hypothyroidism and is taken daily to maintain normal hormone levels.

    • Effectiveness: Levothyroxine is highly effective in restoring normal thyroid hormone levels, but patients must take it for life and have regular blood tests to monitor their TSH levels.

  2. Liothyronine (Cytomel)

    • How it works: Liothyronine is another synthetic bioidentical human thyroid hormone but its triiodothyronine (T3) form, the active form of thyroid hormone. In some cases, doctors prescribe liothyronine in addition to levothyroxine if T3 levels remain low.

    • Effectiveness: While levothyroxine is usually sufficient, liothyronine may be helpful for patients who don’t feel fully symptom-free on T4 alone.

  3. Natural Desiccated Thyroid (NDT) (Armour Thyroid, Nature-Throid)

    • How it works: NDT is made from the thyroid glands of pigs and contains both T4 and T3. Yes, it’s a more natural alternative to synthetic bioidentical human thyroid hormones but may vary in potency which makes dosing quite challenging. Because of this reason, some of my colleagues and myself avoids this option in some if most patients.

    • Effectiveness: While some patients prefer NDT, it is less commonly prescribed than levothyroxine due to its variability in hormone content.

Each patient’s treatment plan will depend on their unique circumstances, including the severity of their hypothyroidism, their response to medication, and any other health conditions they may have.

Personalized Treatment for Every Patient

It’s important to note that every patient is different, and treatment for hypothyroidism must be personalized. Your doctor will work with you to monitor your thyroid hormone levels regularly, adjusting your medication dose to ensure optimal treatment. Some patients may need only levothyroxine, while others may benefit from a combination of medications.

Conclusion

Hypothyroidism is a common condition that can be easily managed with early detection and proper treatment. Left untreated, hypothyroidism can lead to serious complications, but with regular screenings, medications, and careful monitoring, most people with hypothyroidism can live healthy, symptom-free lives. If you’re at risk for hypothyroidism or experiencing symptoms, talk to your healthcare provider about getting screened and developing a personalized treatment plan.

References:

  • American Thyroid Association. (2014). Guidelines for the Treatment of Hypothyroidism: Prepared by the American Thyroid Association Task Force on Thyroid Hormone Replacement. Thyroid, 24(12), 1670-1751. https://doi.org/10.1089/thy.2014.0028

  • Jonklaas, J., Bianco, A. C., Bauer, A. J., Burman, K. D., Cappola, A. R., Celi, F. S., ... & Wartofsky, L. (2014). Guidelines for the treatment of hypothyroidism: prepared by the American Thyroid Association task force on thyroid hormone replacement. Thyroid, 24(12), 1670-1751. https://doi.org/10.1089/thy.2014.0028