Functional Medicine

a woman shaking hands with a doctor

Functional Medicine is a perspective on patient care that aims to get at the root cause of disease. It makes full use of the best of traditional medical testing and treatment, while recognizing that some patients require alternative applications of those tools to feel their best.

For example, a Functional Medicine doctor may order all of the same blood tests as a traditional physician, but may supplement them with more in-depth testing of blood or other bodily fluids to get to the root cause of an issue.

Also, a Functional Medicine doctor will allow for the fact that in order to feel well, some patients need to maintain levels that are either above or below the “normal” range for a particular test. For example, when assessing thyroid function, most traditional caregivers are taught in medical school to go strictly by lab results. In Functional Medicine, the lab results are very helpful, but the primary determinant of treatment is how the patient is feeling.

For treating hormonal imbalances, Functional Medicine doctors also make heavy use of medication titration – the process of making small incremental changes to a patient’s medication dosing and getting their feedback on how it makes them feel before recommending the next incremental change. Through this process, the doctor and patient work as partners to triangulate in on what makes the patient feel their best.

To be effective, Functional Medicine requires more communication between the doctor and patient than would typically occur in a traditional care setting. At Newton Integrative Health, Dr. Katz will meet with each patient for more than an hour initially, and will speak with each patient every few weeks during the initial treatment period to make incremental adjustments to their care. Follow-up consultations and testing typically take place every three months during the first year of care, and then every six months after that.

Thyroid care at Newton Integrative Health is most appropriate for patients who:

  • Have been "ruled out" for hypothyroidism based on normal test levels despite having moderate to severe symptoms consistent with hypothyroidism; or,
  • Are receiving conventional treatments for hypothyroidism -- such as levothyroxine or Armour Thyroid – but are still feeling badly.

If you have not yet explored conventional treatments for hypothyroidism with your primary care physician or endocrinologist, you may wish to do so before making an appointment to see Dr. Katz, as commonly prescribed medications will work for many people. Treatment with Dr. Katz is ideal for those who are not feeling better from these conventional approaches.

About Hypothyroidism

Primary hypothyroidism, or underactive thyroid disease, is a common condition affecting tens of millions of people. It occurs when the thyroid gland does not produce enough thyroid hormone to satisfy the rest of the body's needs – or when the gland has been ablated or surgically removed. The body responds to this insufficiency by slowing down its rate of metabolism -- the process by which we create energy from food. With reduced energy, hypothyroid patients often feel sluggish physically and mentally. Sudden weight gain is also common as the body may sharply reduce the amount of food it burns.

With severe hypothyroidism, patients will experience chronic fatigue, needing frequent naps and/or needing to go to bed much earlier than others. They may also experience difficulty getting out of bed in the morning. Others may battle significant "brain fog" that interferes with their work and everyday interactions. Additional common symptoms include muscle aches, hair loss, digestive problems (constipation, irritable bowel), severe PMS, sleep disturbance, mood disorders, and infertility.

What is “Subclinical Hypothyroidism?”

A subclinical condition is one that does not produce test results that confirm its existence. In other words, it is not detectable through common testing.

Subclinical hypothyroidism occurs when a patient’s TSH and Free T4 test results are within the “normal range” but the patient still suffers from some or all of the symptoms described above. In many cases, even the more revealing Free T3 and Reverse T3 tests may appear normal. For such patients, a classicly-trained endocrinologist or primary care physician may conclude that the patient does not have a thyroid problem – that their symptoms must be due to aging, psychological disorders, or any number of unrelated diseases.

Functional Medicine is ideal for patients with subclinical hypothyroidism, as it prioritizes the patient’s symptoms in determining the course of care.

Functional Treatment for Hypothyroidism

When you become a new patient, Dr. Katz will review your detailed medical history prior to your initial consultation. She will also order extensive blood tests – including a complete thyroid panel – as well as other tests that can help diagnose what is going in. You can get these tests done at any lab you choose – your local hospital, a chain like Quest Diagnostics, or even your primary care doctor’s office if they offer testing there.

Dr. Katz will meet with you for a one-hour in-depth consultation to understand what you're feeling now, how these symptoms have evolved over the course of your life, and what your health goals are going forward. She’ll review the test results with you and give you her thoughts on what may be going on and her recommendations for next steps.

Typically, Functional Medicine treatment for hypothyroidism involves starting you a small dose of thyroid hormone replacement, and then getting your feedback in two weeks as to how you are feeling. At that time, you and Dr. Katz would likely make a small adjustment to your hormone intake based on your feedback. She’ll ask you to report back to her again in two weeks to let her know how you are doing, and you will likely make another adjustment with her at that time. This process will continue every two weeks for the first three months or so until you find the medication and dosing that make you feel best.

Follow-up consultation with lab testing are generally every three months during the first year of care and then every six months thereafter. If you need adjustments to your medications or other aspects of your care plan in between appointment, just reach out with a call or an email and Dr. Katz will help you by phone.

In addition to being an MD, Dr. Katz is also a Registered Dietitian. In addition to prescription medication she can recommend nutritional supplements, dietary modifications, and lifestyle adjustments that help patients with hypothyroidism to feel better.


Functional medicine testing is far more comprehensive than tests typically ordered in a primary care setting. Test panels may be run on your blood, saliva, urine and/or stool, and may cover:

  • Food sensitivities
  • Nutrient levels
  • Leaky gut
  • Parasites, bacteria and fungi
  • Autoimmune deficiencies
  • Metabolic function
  • Adrenal and other hormone function
  • Neurotransmitter balance
  • Genetic testing


There is no such thing as a standard treatment plan at NIHS -- your treatment is customized to your unique circumstances and priorities. Treatment may include prescriptions for medications and/or nutritional supplementation, modifications to your diet and/or lifestyle, and further education and counseling.

At the conclusion of the initial consultation, Dr. Katz will review with you all of your options for testing, as well as any dietary or lifestyle modifications she recommends before any testing begins. She will explain the pros and cons of each option you have, and work with you to select the one(s) best for you.

Many panels are quite extensive, with some producing as many as 100 different data points about your body chemistry to help Dr. Katz confirm or rule out potential causes of your illness.


Testing with NIHS includes having the doctor: 1) order the tests; 2) teach you how to use the test kits; 3) study and interpret the results; and, 4) meet with you in a follow-up appointment to review the results and their meaning. In this appointment Dr. Katz will explain your options for treatment and her recommendations based on the results, and you will decide together on your course of care. (Please note we do not do testing in-house; we will order the appropriate test kit for you.)

Some treatments can be self-managed. Others require follow-up visits and/or consultations by phone, especially in the beginning while you and Dr. Katz are working together to see how your body responds.

This process of incrementally adjusting your medication, therapies, diet, and/or lifestyle habits is a core principle of functional medicine. It is how you and Dr. Katz can hone in on "the sweet spot" where you’re feeling as close to optimal as possible.

Dr. Katz’s approaches to treatment aren’t for everyone. If you or Dr. Katz believe that you are aren’t a good fit for her practice, she will do her best to recommend an appropriate caregiver who may be in a better position to help you.


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