Thyroid disorders include hypothyroidism (underactive thyroid, ICD-10 E03.9) and hyperthyroidism (overactive thyroid, ICD-10 E05.90), and they affect roughly 20 million Americans — about 60% of whom are unaware they have a problem (American Thyroid Association, 2024). The thyroid is a small gland in the front of the neck that controls how every cell in the body uses energy. When it under- or over-produces hormone, it shows up as fatigue, unexplained weight change, mood shifts, heart-rate changes, and temperature intolerance. The first-line test is a TSH (thyroid-stimulating hormone) level — the American Thyroid Association considers the normal range roughly 0.5 to 4.0 mIU/L (ATA 2014 hypothyroidism guideline). Viva Medical Center in Doral, FL runs the full thyroid panel, identifies the cause when treatment is needed, and manages it long-term in primary care — bilingual English and Spanish, in-network with major carriers, with same-day appointments for new symptoms and telehealth follow-ups for stable patients.
Hypothyroidism — Underactive Thyroid
Hypothyroidism is the most common thyroid disorder in the United States. The most common cause is Hashimoto's thyroiditis — an autoimmune condition in which the body's immune system gradually damages the thyroid (NIDDK, 2024). When the thyroid does not make enough hormone, the entire body slows down. Patients describe waking up tired even after 8 hours of sleep, dry skin and brittle hair, slow weight gain over months, cold intolerance, constipation, and a mental sluggishness that is hard to put into words. In women, irregular or heavy periods are common.
- Symptoms — fatigue, cold intolerance, weight gain, dry skin, hair thinning, constipation, low mood, slowed thinking
- First-line test — TSH level (normal range approximately 0.5 to 4.0 mIU/L per ATA 2014)
- Confirmatory tests — Free T4, sometimes Free T3, and anti-TPO antibodies if Hashimoto's is suspected
- Treatment — thyroid hormone replacement, dosed by weight and TSH, with repeat labs at 6 to 8 weeks after starting or adjusting
- Long-term — most patients reach a stable dose and are monitored once a year by TSH
- Coordination — referral to endocrinology for difficult dosing, large goiter, or pregnancy
Hyperthyroidism — Overactive Thyroid
Hyperthyroidism is less common than hypothyroidism but more dramatic in presentation. The most common cause in the United States is Graves' disease, an autoimmune condition that drives the thyroid to overproduce hormone (Endocrine Society 2016 hyperthyroidism guideline). Patients often describe a heart that races at rest, unintentional weight loss despite a normal or increased appetite, anxiety, irritability, heat intolerance and sweating, hand tremor, and difficulty sleeping. In older adults, atrial fibrillation can be the presenting sign.
- Symptoms — palpitations, anxiety, weight loss despite eating, heat intolerance, tremor, insomnia, eye prominence in Graves'
- First-line test — TSH (suppressed, often below 0.1 mIU/L) with elevated Free T4 and Free T3
- Confirmatory tests — TSI (thyroid-stimulating immunoglobulin) for Graves', thyroid uptake scan for nodular disease
- Treatment options — antithyroid medications, radioactive iodine, or surgery, coordinated with endocrinology
- Cardiac safety — heart-rate control is the first priority when palpitations or atrial fibrillation are present
- Eye involvement — referral to ophthalmology when Graves' eye disease is suspected
Who Should Be Screened for Thyroid Disease
The U.S. Preventive Services Task Force concluded in 2015 that current evidence is insufficient to recommend universal screening for asymptomatic adults (USPSTF 2015 thyroid statement). However, both the American Thyroid Association and the American Association of Clinical Endocrinologists recommend checking TSH when symptoms suggest thyroid disease, in adults over 60, in women planning pregnancy, in patients with autoimmune disease or strong family history, and in anyone with a goiter (visible neck swelling) or thyroid nodule.
- Adults with symptoms — fatigue, weight change, mood changes, heart-rate changes, temperature intolerance
- Women planning pregnancy or in the first trimester — uncontrolled thyroid disease affects fetal development
- Adults over 60 — symptoms are easy to attribute to aging and can be missed
- Patients with autoimmune disease — type 1 diabetes, celiac, lupus, rheumatoid arthritis increase risk
- Strong family history of thyroid disease — siblings and parents are the highest-risk relatives
- Visible neck swelling or a palpable nodule — needs ultrasound and possibly biopsy
Thyroid and Pregnancy
Thyroid hormone is essential for fetal brain development in the first trimester, when the baby relies entirely on the mother's supply. The American Thyroid Association's 2017 pregnancy guideline recommends a TSH target below 2.5 mIU/L in the first trimester for women already on thyroid hormone replacement, and prompt evaluation for any woman with new symptoms or known thyroid disease who is planning pregnancy or newly pregnant. Dosing typically needs to increase by 20% to 30% during pregnancy.
- Preconception — confirm TSH is in target range before conception when possible
- First trimester — TSH target below 2.5 mIU/L in patients on hormone replacement (ATA 2017)
- Dose adjustment — most patients on hormone replacement need a 20% to 30% dose increase
- Postpartum thyroiditis — about 5% to 10% of women develop transient thyroid dysfunction in the first year after delivery
- Coordination — OB-GYN works directly with primary care or endocrinology on labs and dosing
Thyroid and Weight — An Honest Conversation
One of the most common reasons patients ask for a thyroid test is unexplained weight gain. The honest medical reality is more limited than the public narrative suggests. When hypothyroidism is genuinely present and untreated, modest weight gain — typically 5 to 10 pounds of water and slowed metabolism — is real, and weight tends to normalize after treatment. However, thyroid hormone replacement is not a weight-loss medication. Using it in a patient with a normal TSH does not help with weight loss and carries real cardiac and bone-density risks (American Association of Clinical Endocrinologists position statement).
- If TSH is elevated and symptoms fit — treatment may restore a small amount of weight, energy, and metabolism
- If TSH is normal — thyroid medication is not appropriate for weight loss
- Medical weight management — see our medical weight management program for evidence-based, supervised options
- Common other causes of weight gain to evaluate — sleep, insulin resistance, mood, medication side effects, perimenopause
What to Expect at Your First Visit
A new-patient thyroid evaluation in our Doral office is scheduled for 45 to 60 minutes — long enough to take a careful history, examine the neck, and explain the lab plan before any blood is drawn. Most patients walk out the same day with their lab order, an understanding of which numbers we care about, and a follow-up plan.
- History (20 min) — current symptoms, family history, medications, supplements that affect the thyroid (biotin, iodine, certain mood-stabilizing medication classes)
- Physical exam (10 min) — neck palpation for goiter or nodule, pulse, blood pressure, reflexes, skin and hair
- Lab order — TSH first, with Free T4, Free T3, and antibodies reflexed in based on the initial result
- Plan discussion — what each number will tell us, when we will repeat labs, and when treatment would start
- Follow-up — typically 6 to 8 weeks after starting or changing thyroid hormone replacement, then annually when stable
Insurance and Bilingual Care
Viva Medical Center is in-network with the major insurance carriers serving Miami-Dade. Thyroid panels, follow-up visits, and prescribed treatment fall under your plan's primary care or laboratory benefit. Our front desk verifies your specific plan before the first visit so there are no surprises.
- In-network carriers — Oscar Health, Aetna, Cigna, Humana, Medicare Advantage, Ambetter, UnitedHealthcare
- Self-pay rates available with transparent pricing — no surprise bills
- Bilingual care — intake, visits, telehealth, and patient portal in English and Spanish
- Same-day visits — frequently available for new symptoms; book online or call (305) 209-0001
- Telehealth follow-ups — convenient for stable patients reviewing recent labs
Sources
- American Thyroid Association — Patient Information & Guidelines — American Thyroid Association
- Hypothyroidism (Underactive Thyroid) — NIDDK — National Institute of Diabetes and Digestive and Kidney Diseases (NIH)
- USPSTF — Thyroid Dysfunction: Screening (2015) — U.S. Preventive Services Task Force
- Endocrine Society — Hyperthyroidism and Other Causes of Thyrotoxicosis Guideline — Endocrine Society
Frequently Asked Questions
What are the symptoms of hypothyroidism versus hyperthyroidism?
Hypothyroidism (underactive thyroid) slows the body down: fatigue, weight gain, cold intolerance, dry skin, hair thinning, constipation, low mood, and slowed thinking. Hyperthyroidism (overactive thyroid) speeds it up: palpitations, weight loss despite a normal or larger appetite, heat intolerance, sweating, tremor, anxiety, and insomnia. Symptoms overlap with many other conditions, which is why a TSH blood test is the right first step rather than guessing from symptoms alone.
Who should be screened for thyroid disease?
The American Thyroid Association recommends a TSH test in adults with any of the symptoms above, in women planning pregnancy or newly pregnant, in adults over 60, in anyone with an autoimmune condition or strong family history of thyroid disease, and in anyone with a goiter or palpable nodule. The USPSTF concluded in 2015 that universal screening of asymptomatic adults is not currently recommended, but symptom-driven testing is well-established.
How often should I get my TSH tested?
After starting or adjusting thyroid hormone replacement, TSH is rechecked at 6 to 8 weeks. Once stable on a dose, most patients need a TSH once a year. In pregnancy, testing is more frequent — typically each trimester and 6 weeks postpartum. For patients with thyroid antibodies but normal TSH, annual or biannual monitoring is reasonable. Your provider will set the exact cadence based on your numbers and risk.
What should I expect from treatment?
For hypothyroidism, thyroid hormone replacement is taken daily, usually first thing in the morning on an empty stomach, and most patients reach a stable dose within 2 to 3 months. Symptoms improve gradually — energy and mood often improve in the first month; hair, skin, and weight changes can take several months. For hyperthyroidism, treatment depends on the cause and may involve antithyroid medications, radioactive iodine, or surgery, coordinated with endocrinology.
Does the thyroid affect weight, and can thyroid medication help me lose weight?
Thyroid hormone affects metabolism, so untreated hypothyroidism can cause a modest weight gain — typically 5 to 10 pounds of water and slowed metabolism — that tends to normalize after treatment. However, thyroid hormone replacement is not a weight-loss medication. Using it in a patient with a normal TSH does not produce weight loss and carries real risks to the heart and bones. If weight is your concern and your TSH is normal, our medical weight management program is the right place to start.
I am planning pregnancy. Should I have my thyroid checked?
Yes. Thyroid hormone is essential for fetal brain development in the first trimester. The American Thyroid Association recommends a TSH check before conception when possible. Women already on thyroid hormone replacement typically need a 20% to 30% dose increase during pregnancy, and TSH should be kept below 2.5 mIU/L in the first trimester (ATA 2017 pregnancy guideline). We coordinate directly with your OB-GYN.
What is Hashimoto's and what is Graves' disease?
Hashimoto's thyroiditis is the most common cause of hypothyroidism in the United States — an autoimmune condition in which the immune system gradually damages the thyroid. It is diagnosed by anti-TPO antibodies and is treated with thyroid hormone replacement. Graves' disease is the most common cause of hyperthyroidism — also autoimmune, but in this case the antibodies stimulate the thyroid to overproduce hormone. It is treated with antithyroid medications, radioactive iodine, or surgery, depending on severity and patient preference.
Does insurance cover thyroid testing and treatment?
Yes for our in-network carriers — Oscar Health, Aetna, Cigna, Humana, Medicare Advantage, Ambetter, and UnitedHealthcare. TSH and basic thyroid labs are routine preventive or diagnostic labs, and follow-up visits fall under the primary care benefit. Our front desk verifies your specific plan before the first visit. Self-pay rates are available with transparent pricing.
Do you offer bilingual care?
Yes. All services — intake, visits, telehealth follow-ups, lab review, and patient portal communication — are available in English and Spanish. Roughly two-thirds of the patients we see for thyroid evaluation prefer Spanish, and our entire clinical team is bilingual.
Can I be seen by telehealth for thyroid follow-up?
The first visit is best in person because we need to examine the neck and check vitals. Once we have your labs and treatment plan, follow-up visits — lab reviews, dose adjustments, annual check-ins on a stable dose — work well by telehealth. Telehealth is available across Miami-Dade and throughout Florida for established patients.