Hypothyroidism, also called an underactive thyroid, is a condition in which the thyroid gland does not produce enough thyroid hormone. The thyroid is a small, butterfly-shaped gland located in the front of the neck that helps regulate your body’s metabolism, heart rate, body temperature, digestion, and energy levels.
When thyroid hormone levels are too low, many of the body’s normal functions slow down. Symptoms often develop gradually and may not be noticeable at first. Hypothyroidism is very common and is usually a lifelong condition. Fortunately, it can almost always be managed successfully with daily thyroid hormone replacement medication.
Hypothyroidism – NIH MedlinePlus
https://medlineplus.gov/hypothyroidism.html
Provides easy-to-understand information about hypothyroidism, including symptoms, diagnosis, treatment, and long-term management.
Hypothyroidism (Underactive Thyroid) – American Thyroid Association
https://www.thyroid.org/hypothyroidism/
Explains what hypothyroidism is, why it develops, treatment options, and common questions.
Hypothyroidism is one of the most common endocrine (hormone) disorders. It affects millions of people in the United States and is more common in women than men. The risk increases with age and in people with autoimmune diseases or a family history of thyroid disorders.
American Thyroid Association – Hypothyroidism
https://www.thyroid.org/hypothyroidism/
Provides information about who is most likely to develop hypothyroidism and common risk factors.
What Symptoms Might You Notice?
Symptoms often develop slowly over months or years and can vary from person to person.
Common symptoms may include:
Your healthcare provider will review your symptoms, perform a physical examination, and order blood tests to measure your thyroid hormone levels.
Most people are diagnosed using a combination of Thyroid-Stimulating Hormone (TSH) and Free T4 blood tests.
Hypothyroidism – NIH MedlinePlus
https://medlineplus.gov/hypothyroidism.html
Explains how hypothyroidism is diagnosed and monitored.
Several conditions can reduce thyroid hormone production.
Common causes include:
Hypothyroidism – NIH MedlinePlus
https://medlineplus.gov/hypothyroidism.html
Learn about the common causes of hypothyroidism and risk factors.
Several factors can worsen symptoms or interfere with thyroid hormone treatment.
Common factors include:
American Thyroid Association
https://www.thyroid.org/
Provides practical guidance on taking thyroid medications correctly and managing hypothyroidism.
Not all cases of hypothyroidism can be prevented, especially those caused by autoimmune diseases such as Hashimoto’s thyroiditis. However, early diagnosis and treatment can help prevent complications.
Helpful prevention tips include:
American Thyroid Association
https://www.thyroid.org/
Provides practical information about thyroid health, medication management, and long-term care.
The following video content is provided to help you better understand this condition. These resources are intended for educational purposes and should not replace personalized medical advice from your healthcare provider.
Laboratory testing is the primary way hypothyroidism is diagnosed and monitored.
Common laboratory tests may include:
TSH Test – NIH MedlinePlus
https://medlineplus.gov/lab-tests/tsh-thyroid-stimulating-hormone-test/
Explains how TSH testing is used to diagnose and monitor hypothyroidism.
Most people with hypothyroidism do not require imaging studies. However, additional testing may be recommended if thyroid enlargement or nodules are present.
Common diagnostic tests include:
American Thyroid Association – Thyroid Function Tests
https://www.thyroid.org/thyroid-function-tests/
Provides information about thyroid blood tests, ultrasound, and thyroid nodule evaluation.
Treatment focuses on replacing the thyroid hormone your body is unable to produce.
Treatment options may include:
Hypothyroidism – American Thyroid Association
https://www.thyroid.org/hypothyroidism/
Provides information about treatment options and long-term management of hypothyroidism.
Healthy lifestyle habits can support thyroid health and improve overall well-being.
Helpful lifestyle changes include:
American Thyroid Association
https://www.thyroid.org/
Provides practical guidance for living well with hypothyroidism.
Most people with hypothyroidism are treated with thyroid hormone replacement medication.
Common medications include:
Levothyroxine – NIH MedlinePlus
https://medlineplus.gov/druginfo/meds/a682461.html
Provides information about levothyroxine, proper use, side effects, and monitoring.
Most people with hypothyroidism do not require surgery or invasive procedures. Treatment usually involves taking thyroid hormone replacement medication and having regular blood tests to monitor thyroid hormone levels. However, certain procedures may be recommended if thyroid nodules, an enlarged thyroid (goiter), or thyroid cancer is suspected.
Common procedures may include:
American Thyroid Association
https://www.thyroid.org/
Learn about thyroid ultrasound, biopsies, surgery, and long-term thyroid monitoring.
Hypothyroidism is usually a lifelong condition. With proper treatment, most people live healthy, active lives and experience significant improvement in their symptoms.
Your healthcare provider will monitor your thyroid hormone levels regularly and adjust your medication if needed. It is important to continue taking your medication every day, even if you feel well.
Daily self-care is important for managing hypothyroidism and maintaining healthy thyroid hormone levels.
Helpful tips include:
Hypothyroidism – American Thyroid Association
https://www.thyroid.org/hypothyroidism/
Provides practical guidance on taking thyroid medication correctly and living with hypothyroidism.
Most people with hypothyroidism require lifelong treatment with thyroid hormone replacement. Your healthcare provider will determine the best treatment plan based on the cause of your condition.
Yes. Low thyroid hormone levels can slow your metabolism, making weight gain more likely. Treating hypothyroidism may help improve metabolism, although healthy eating and regular exercise remain important.
Yes. Fatigue is one of the most common symptoms of hypothyroidism and often improves after treatment begins.
Some medications and supplements, especially calcium and iron, can interfere with thyroid hormone absorption. Always ask your healthcare provider or pharmacist how to take your medications correctly.
Thyroid blood tests are commonly checked 6–8 weeks after starting or changing medication and then periodically once your levels are stable.
Consider asking your healthcare provider:
Many people with hypothyroidism receive care from their primary care provider. Depending on your condition, your provider may recommend seeing a specialist.
You may be referred to:
American Thyroid Association
https://www.thyroid.org/
Provides patient education about thyroid disorders, specialists, and treatment options.
Most cases of hypothyroidism are not curable, particularly when caused by Hashimoto’s thyroiditis, the most common cause. However, hypothyroidism is highly treatable with daily thyroid hormone replacement medication.
Most people experience significant improvement in symptoms once thyroid hormone levels return to a normal range, and many live healthy, active lives with ongoing treatment.
Call 911 or seek emergency medical care immediately if you experience:
These symptoms may be signs of myxedema coma, a rare but life-threatening complication of severe untreated hypothyroidism.
Seek prompt medical evaluation if you notice:
Hypothyroidism – NIH MedlinePlus
https://medlineplus.gov/hypothyroidism.html
Learn about hypothyroidism, possible complications, and when emergency medical care is needed.
CALL 911
APNS does not provide emergency medical services. If you believe you are experiencing a medical emergency, including (but not limited to) chest pain, difficulty breathing, stroke symptoms, severe allergic reactions, anaphylaxis, uncontrolled bleeding, seizures, loss of consciousness, or any other potentially life-threatening condition, you are instructed to call 911 immediately or go immediately to the nearest emergency department.
Hypothyroidism – NIH MedlinePlus
https://medlineplus.gov/hypothyroidism.html
Easy-to-understand information about hypothyroidism, including symptoms, diagnosis, treatment, and living with an underactive thyroid.
American Thyroid Association – Hypothyroidism
https://www.thyroid.org/hypothyroidism/
Comprehensive patient education about hypothyroidism, thyroid hormone replacement, laboratory monitoring, and frequently asked questions.
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
https://www.niddk.nih.gov/health-information/endocrine-diseases
Reliable information about thyroid disease and other endocrine disorders.
Hormone Health Network
https://www.hormone.org/
Evidence-based patient education about thyroid disorders, hormone health, and endocrine conditions.
This guide is intended for educational purposes only and should not replace medical advice, diagnosis, or treatment from your healthcare provider. Always follow the recommendations of your healthcare team regarding your individual health needs. Contact your healthcare provider if your symptoms worsen, new symptoms develop, or your medication is no longer controlling your hypothyroidism. Call 911 immediately if you experience severe difficulty breathing, chest pain, loss of consciousness, severe confusion, or symptoms of myxedema coma or another medical emergency.
At APNS, our providers take the time to understand your condition and your goals. We offer comprehensive telehealth visits at a fixed rate — no membership fees, no insurance required, and no unexpected charges. Whether you’re newly diagnosed or looking for a provider who actually listens, we’re here to help.
