Hashimoto's Root Cause: What a Functional Approach Looks At
"I would wake up in the middle of the night with this heartburn that felt like a heart attack." That is how Brandi Bradley describes the months before her Hashimoto's diagnosis in 2019. The answer her story points to is a root-cause approach: it looks past a single TSH number at the gut, the liver, the nervous system and the wider picture, and it runs alongside your medical care.
Brandi joined me on the Talking Nutrition podcast, episode 199. She is a functional health practitioner who has Hashimoto's herself. Everything here is education and does not replace your doctor, and anything that feels like chest pain needs a medical check. For the basics, my post on what Hashimoto's is covers the autoimmune mechanism, antibodies and the gluten evidence, so I leave those out.
What Sent Brandi Looking for Answers?
Brandi coached macro tracking and weight loss online before she moved into gut and hormone health. In 2019 she was about a year postpartum and chasing a physique goal, and six months of lowering her intake had taken her to roughly 1,300 calories.
She had also switched contraception around then and names it as one of the stressors, though that choice sits between a woman and her own doctor.
Then her digestion fell apart. She was doubled over in pain most nights and saw several doctors about it before going looking on her own.
Working in the health industry, she knew which labs she wanted. Getting them took effort. "I had to push and push and push," she told me. The diagnosis was Hashimoto's. Her next steps, as she tells it, were Brazil nuts for the selenium and levothyroxine. She took the levothyroxine for six months, then came off it.
Brandi tells her story best herself, so here is the full conversation.
What Does a Root-Cause Approach to Hashimoto's Mean?
"Root cause" gets used like a promise, so let me pin it down. Hashimoto's can have several causes at once, and Brandi said so plainly:
There's never one root cause and that is incredibly hard to accept as a woman or a man going through systemic issues or just being diagnosed and not feeling like yourself.
In her own case she sees layers stacked on each other: a long deficit, the contraception change, acute infections in her digestive tract and a lot of stress. Underneath those she traces the internal imbalance to her digestion, her liver function and the inflammation she carried.
A functional approach to Hashimoto's adds questions while the thyroid is still being monitored. How well do you digest food? How much load does your nervous system carry? The medication, the antibody tracking and the repeat labs stay with your doctor.
Here is where I slow down. Brandi uses the word healed for her own experience, and says her thyroid levels have held for four and a half years since she stopped medication. I take her at her word about her body, and I would not promise that outcome to anyone. There is no cure for Hashimoto's, and diet does not reverse an autoimmune process already underway. What is possible is easing symptoms, supporting the parts you can influence and, in some people, lowering antibodies or slowing further damage, none of it guaranteed. Plenty of women stay on thyroid medication for years and feel well, and stopping is a call for the prescriber. Brandi herself says "medication needs to be there for certain things."
Why Do the Gut and Liver Keep Coming Up?
TSH is a pituitary hormone, a message from the brain asking the thyroid to work. T4 is what the thyroid mostly releases, and T3 is the active form that reaches your cells. Brandi pointed out that the step from T4 to T3 leans on the gut and the liver, which is her reason for saying the thyroid cannot be looked at alone. I find that a useful lens.
She calls the liver the powerhouse organ, with more than 500 processes, among them clearing hormones such as oestrogen and cortisol. A five-day cleanse can be unsafe, she said, and she prefers gentle support through food and nervous system regulation, matched to the person.
For the gut side, my post on improving digestion is where I send people first. If heartburn is part of your picture, as it was for Brandi, it has several possible causes, and I cover one in my post on low stomach acid. A burn that keeps coming back belongs with your doctor.
What Does a Hashimoto's Flare-Up Look Like?
The episode answers this only for Brandi. She runs a business, has children aged six and two and sits at a computer eight hours a day. When a hard season stretches on, she watches her energy. "It's usually the energy. It's usually the brain fog." Mid-afternoon crashes join them after a long grind, and her cycle stays quiet. She then pulls back and works on her nervous system first.
She has not tested her antibodies at those moments. These are signals she learnt over years in her own body, so read them as her pattern. Fatigue and brain fog also come from low iron or short sleep, and only your doctor can say which applies. What I take from her is the habit of noticing what changes first when life gets heavy. For the wider symptom picture, see my post on hypothyroidism symptoms.
Where does thyroid hormone conversion actually sit?
Brandi pointed to the gut and the liver. The Thyroid Decoder carries a TSH-to-T4-to-T3 conversion map that shows the whole path and where it can slow down.
Get the free Thyroid Decoder →
Where Does the Nervous System Fit?
Brandi puts the nervous system ahead of any protocol, on the reasoning that a body under constant push has little left for anything else. "Your body can only heal if it feels safe." She reads an inability to sit still as a sign of a stressed system. That is her interpretation, and I treat it as a lens.
I can vouch for the restlessness. When I started meditating I fidgeted, got impatient, opened my eyes to check the timer or fell asleep. A few months of showing up passed before it started to work. Now I give clients a ten-minute stillness task: sit, no music, do what you like with it. It is the hardest task I set, and the one they talk about most warmly afterwards. My post on managing stress covers the practical side.
What Can Functional Testing Show?
Brandi's testing story has a twist I appreciated. Earlier in her coaching she took women straight into a GI map and a gut protocol, because the gut looked like the main source of trouble:
I was running it and pushing them for 10 weeks and nothing would shift. And it was because there were deeper root issues at hand.
Her fix was to ask what sits upstream, such as blood sugar and stress load, before committing to a gut protocol. A GI map describes what lives in the gut at one point in time, and a hormone panel such as DUTCH tracks hormones and their breakdown products across a day. A result shows where to look. Deciding what to do about it takes someone who knows your history.
The conversation also lands on over-testing. Ordering thyroid, metabolic and sex hormone markers all at once can produce more answers than anyone can act on. Whether any test suits you is a conversation for your doctor or practitioner, and I describe them without recommending one. In Norway, where I live, a doctor wants a clear reason before adding to a panel, which I understand when resources are limited.
Why Do Cycles and Hormones Come Into It?
I opened the episode describing a culture of grinding. We earn our sleep and diet too much, and some women lose their periods. I mentioned a client who had gone a year without one, with low calories, plenty of running and days of constipation behind her.
Brandi left a stranger's case alone and described the questions she asks first. Sex hormones sit downstream of other systems, so she keeps asking what regulates what, and she tends to land on inflammation, blood sugar or the liver.
Stress gets its own mention. "I can't even tell you how sensitive our cycles are to stress." Her example is travel. If you ovulate around day 15 and fly out on day 11, the trip can push ovulation back and lengthen the cycle, even when the trip is fun. Sleep belongs in this picture too, and my post on sleep deprivation and weight loss covers it. A period that disappears for months deserves a medical workup, because some causes need a doctor to rule in or out.
What If Your Doctor Says You Are Fine?
Brandi's own answer was persistence. She went back, asked again and arrived knowing what she wanted checked. I would add something from my side of the table. GPs often get about fifteen minutes per patient, so a calm, specific request lands better than a general worry. Bring your symptoms with dates and any relatives with thyroid or autoimmune conditions, and ask whether antibodies and the thyroid hormones beyond TSH can be added. If the answer is no, ask what would change it. A second opinion is a normal thing to ask for.
Brandi hopes for more teamwork between doctors and coaches, and her closing point is about the gap between appointments. When the next one is three months away, she asks who is helping in the meantime:
Well, in those three months, who is educating you?
Brandi covers more in the full 57 minutes, including how she sees coaches and doctors working side by side.
Already on medication and still tired?
The Thyroid Decoder has a section for exactly that. It also lists the six markers to ask for and scores your symptoms into bands you can take to your appointment.
Get the free Thyroid Decoder →
Written by Johan Vesters, functional health and nutrition coach (FNMS, HMCC L1, MMU L1, PN1, CFL1, NCI L1) and founder of Odyssey Coaching Systems.