Comprehensive Thyroid Care

Comprehensive Thyroid Care
Exhausted, gaining weight, or just not feeling like yourself… even when you’ve been told your thyroid labs are “normal”?
Expert thyroid care from a dual board-certified endocrinologist who looks at optimal, not just normal.

Thyroid care at Modern Endocrine in Oklahoma City covers the full picture… from hypothyroidism and hyperthyroidism to Hashimoto’s, Graves’ disease, and thyroid nodules.
Led by dual board-certified endocrinologist Dr. Cassie Smith, who has navigated her own autoimmune thyroid disease, our team looks at optimal ranges, not just “normal” ones, and connects your thyroid to your gut, hormones, and metabolism.
We diagnose with thorough testing, perform thyroid biopsies in-office when needed, and build a plan that combines proven treatment with the nutrition and lifestyle support your thyroid actually needs. We don’t guess… we test.

Could my thyroid be the problem, even if my labs are “normal”?
Often, yes. Many people have real thyroid symptoms while their standard labs are read as “normal.” That’s because a normal range isn’t the same as an optimal range, and a single TSH test rarely tells the whole story. We run a fuller thyroid panel… including the active hormones and antibodies… so we can see what’s really happening.
If you’re tired, foggy, cold, gaining weight, or losing hair and have been told everything looks fine, you deserve a closer look. We treat how you feel, not just where your numbers fall on a lab sheet.
What Thyroid Conditions Do You Treat?
Hypothyroidism (underactive thyroid)
Your thyroid isn't making enough of the hormones your body needs, which slows things down. Common symptoms include fatigue, constipation, dry skin, swelling, feeling cold, hair loss, and trouble losing weight.
Hyperthyroidism (overactive thyroid)
Your thyroid makes too much hormone, which speeds your metabolism up. This can cause unintentional weight loss, a rapid or irregular heartbeat, anxiety, tremor, and trouble sleeping.
Hashimoto's disease
An autoimmune condition where the immune system makes antibodies that attack the thyroid. Over time this damage can reduce thyroid function and lead to hypothyroidism if it isn't addressed. It's one of the most common causes of an underactive thyroid.
Graves' disease
An autoimmune condition that pushes the thyroid to overproduce hormones, and a common cause of hyperthyroidism. Like Hashimoto's, it needs proper testing and ongoing management.
Thyroid Nodules
Small lumps or growths that form within the thyroid gland. They are very common, and most are benign, but some may require further evaluation, including a biopsy, to rule out cancer and determine whether they are affecting thyroid function.

Not sure which one fits you?
That’s exactly what we’ll help you figure out. Start with a free discovery call.
Thyroid biopsy (FNA)
If you have a thyroid nodule, we can evaluate it by interpreting your ultrasound report no matter where you live. If a fine needle aspiration (FNA) biopsy is needed we can help facilitate a referral near you. An FNA uses a thin needle to take a small sample of cells from the nodule to tell a benign condition apart from thyroid cancer.
It’s a common, in-office procedure done without sedation, so you won’t need a driver afterward. Most patients have only about 3–5 minutes of downtime after the procedure.


What happens when you come in?
Getting answers is simpler than you think. It starts with a free discovery call to make sure we’re the right fit. From there, we complete a comprehensive thyroid evaluation along with in-depth hormone, insulin, metabolic,micronutrient, and inflammatory testing.
Once your results are in, we’ll sit down with you to review everything in detail and create a personalized plan designed specifically for you. You’ll never feel rushed, and you’ll see the same provider at every visit.
The fastest way to find out what’s going on with your thyroid is to talk to us. Book your free discovery call… it only takes a minute, and there’s no obligation.
Who should see a thyroid specialist?
It may be time for a closer look if you have:
- Fatigue, brain fog, or low energy that won’t lift
- Unexplained weight gain… or unexplained weight loss
- Hair thinning, dry skin, or feeling cold all the time
- A racing or irregular heartbeat, anxiety, or tremor
- A thyroid nodule or family history of thyroid disease
- A Hashimoto’s or Graves’ diagnosis that still isn’t under control
- “Normal” thyroid labs but symptoms that say otherwise



Why choose Modern Endocrine for thyroid care?
Modern Endocrine is the only functional health clinic in Oklahoma City led by a dual board-certified endocrinologist… and thyroid care is core to what we do. We combine conventional treatment with root-cause testing, and we manage everything from medication to in-office biopsies under one roof.
- Led by a dual board-certified endocrinologist who treats thyroid disease… and has lived it
- Optimal-range testing and full thyroid panels, not just a single TSH
- In-office FNA thyroid biopsies or coordination of biopsies near you… no outside referral needed
- We connect your thyroid to your gut, hormones, and metabolism
- A full hour to review your results, and the same provider every visit
- In person in OKC + telehealth in 46 states
How much does thyroid care cost, and do you take insurance?
Modern Endocrine is a cash-pay (self-pay) clinic, so your care plan is driven by your health… not by insurance rules. We accept HSA and FSA cards, major credit cards, and offer payment plans. The best place to start is a free discovery call, where we’ll explain what your thyroid evaluation and care would include and cost.
Dr. Cassie Smith, MD
Dr. Cassie Smith is the founder of Modern Endocrine in Oklahoma City and is dual board-certified in endocrinology and internal medicine. Her own path with autoimmune thyroid disease… from Graves’ disease to Hashimoto’s… is part of why she pursued an endocrinology fellowship and now helps patients find answers others miss.
She completed her residency at the University of Missouri Kansas City School of Medicine and her fellowship at the OU Health Sciences Center and Harold Hamm Diabetes Center.
Named a Top Doctor by 405 Magazine, she is the author of an amazon best selling book“Fix Your Gut, Fix Your Hormones: The Critical Connection Your Doctor Is Missing…And Why You Still Feel Terrible Despite “Normal” Labs” and host of the podcast “Hormones, Metabolism, and You.”

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Frequently asked questions
Your thyroid is a small gland in your neck that makes hormones controlling your metabolism, energy, weight, temperature, heart rate, mood, and more. When it makes too little or too much hormone, you feel it all over your body.
A proper thyroid evaluation usually goes beyond TSH alone. Depending on your symptoms and history, this may include TSH, Free T4, Free T3, reverse T3 and thyroid antibodies, along with other labs that can affect how thyroid hormone is made, converted, and used in the body like insulin, cortisol, crp, ferritin, iodine, vitamin d, vitamin b12, and a GI Map.
Common signs include fatigue, weight gain, constipation, dry skin, swelling, feeling cold, hair thinning, and brain fog. They often come on slowly and get dismissed as stress or aging.
Unintentional weight loss, a rapid or irregular heartbeat, anxiety, tremor, feeling hot, diarrhea, and trouble sleeping. These can come on more quickly and should be evaluated.
Hashimoto’s is an autoimmune condition in which the immune system makes antibodies that attack the thyroid. Over time it can reduce thyroid function and cause hypothyroidism. It’s one of the most common causes of an underactive thyroid and can lead to other autoimmune conditions, hormone imbalances, and gut dysfunction if left untreated.
Hashimoto’s is an autoimmune condition, so the goal is not just to replace thyroid hormone, but to understand what may be driving the immune attack. While it is not typically considered “curable,” it can absolutely be put into remission, be treated, and often managed much more effectively when you address thyroid function, inflammation, gut health, nutrient deficiencies, and other root causes.
Graves’ is an autoimmune condition that drives the thyroid to overproduce hormones and is a common cause of hyperthyroidism. It needs proper testing and ongoing management as it can lead to other autoimmune conditions if left untreated.
Thyroid antibodies are markers that your immune system may be reacting against your thyroid. Elevated antibodies (TPO or Tg Ab) can suggest autoimmune thyroid disease, such as Hashimoto’s, and may help explain why thyroid symptoms are developing even before standard thyroid labs become clearly abnormal.
A “normal” TSH does not always mean your thyroid is functioning optimally. TSH is simply the signal from the brain telling the thyroid to produce hormone. Your thyroid makes mostly T4, but T4 must be converted into free T3 (FT3) — the active thyroid hormone that actually enters cells and helps drive energy, metabolism, mood, digestion, and more. If that conversion is impaired, or if thyroid hormone is not being used well at the tissue level, you can still have thyroid symptoms even when standard labs appear “normal.” Stress, inflammation, insulin resistance, low ferritin, nutrient deficiencies, hormone imbalance, and gut dysfunction can all play a role. That is why we run a more comprehensive thyroid work-up and look at the bigger picture, not just one number.
Because levothyroxine is T4, and your body still has to convert that into T3, the active thyroid hormone that actually works inside your cells. If that conversion is impaired by stress, inflammation, insulin resistance, gut dysfunction, or nutrient deficiencies, you may still feel hypothyroid even if your TSH looks “normal.”
Not always — it depends on the cause of your thyroid issue. Some patients do need long-term thyroid medication, especially if thyroid damage is significant or their thyroid gland has been removed, while others may also need a broader treatment plan that addresses inflammation, gut health, nutrient status, hormones, and metabolic health alongside medication.
That depends on the person and the underlying cause. Some people start noticing improvement of fatigue and brain fog within a few weeks, while others take longer, especially if there are additional issues like autoimmunity, nutrient deficiencies, gut dysfunction, inflammation, or hormone imbalance that also need to be addressed.
Yes… significantly. Chronic stress, gut dysbiosis, and systemic inflammation can interfere with thyroid hormone conversion, increase immune activation, and make it harder for hormones to work properly at the cellular level
Yes. Thyroid health plays a major role in reproductive hormones, ovulation, menstrual cycles, fertility, and pregnancy. It is especially important in pregnancy because the baby depends on the mother’s thyroid hormone until about 18 weeks gestation, which is why a deeper thyroid evaluation can matter so much for both conception and healthy pregnancy support. We offer thyroid optimization prior to and during pregnancy.
Thyroid nodules can form for several reasons, including thyroid tissue overgrowth, cysts, inflammation, autoimmune thyroid disease, or changes within the gland over time. Sometimes there is a clear reason, and sometimes they simply develop without one obvious cause.
It depends on the type of nodule. Some stay stable for years, some may grow slowly, and some may need treatment or biopsy depending on their size, appearance, symptoms, or function. The first step is understanding exactly what kind of nodule you have and whether it actually needs intervention. Then we determine what we can do to prevent further thyroid nodules from developing.
A fine needle aspiration (FNA) uses a thin needle to sample cells from a thyroid nodule to tell a benign condition from thyroid cancer. It’s done in-office without sedation, you won’t need a driver, and most patients have only about 3–5 minutes of downtime.
Modern Endocrine is a cash-pay clinic, so your plan isn’t limited by insurance rules. We accept HSA/FSA cards, major credit cards, and payment plans. Start with a free discovery call to learn what your care would cost.
Yes. Modern Endocrine is licensed to provide telehealth in 46 states, with in-person care… including FNA biopsies… available in Oklahoma City.
Ready to finally get answers about your thyroid?
Book your free discovery call and let’s take a real look at your thyroid… together. No pressure, no obligation… just answers.

© 2026 Modern Endocrine, All Rights Reserved.
850 NW 58th Street, Oklahoma City, OK 73118
Mon–Fri 8am–5pm
This page is for general education and is not medical advice.
Testing and treatment recommendations are made after evaluation. Individual results vary.
