Last Updated on March 25, 2026 by Carrie Korem, FNTP
If you’ve been diagnosed with Hashimoto’s, one of the first questions you probably had was: why did this happen to me? That’s a really important question, and the good news is that understanding what causes Hashimoto’s disease is the first step toward doing something about it.
In this post, I’ll walk you through what Hashimoto’s is, how it’s diagnosed, what the most common root causes are, and what you can actually do to support your body. Let’s dive in.
What Is Hashimoto’s Disease?
Hashimoto’s is an autoimmune condition. That means your immune system is attacking your own thyroid tissue.
This is a really important point: Hashimoto’s is an immune system problem that affects the thyroid. It is not just a thyroid problem. That distinction matters a lot when it comes to figuring out how to heal.
You might also hear Hashimoto’s called by its other names: Hashimoto’s thyroiditis, chronic lymphocytic thyroiditis, or chronic autoimmune thyroiditis. They all refer to the same condition.
How Is Hashimoto’s Diagnosed?
Hashimoto’s is most often found when certain antibodies show up in your blood. These are called TPO antibodies (thyroid peroxidase antibodies) and TgAb antibodies (thyroglobulin antibodies). When these are elevated, it’s a sign that your immune system is attacking your thyroid.
Here’s something that surprises a lot of people: these antibodies can show up even when your TSH, T4, T3, FT4, and FT3 levels all look normal.
That’s why it’s so important to test for antibodies specifically, and not just rely on a standard thyroid panel.
What Are the Symptoms of Hashimoto’s Disease?
There are literally hundreds of possible symptoms with Hashimoto’s, and they can vary a lot from person to person. Some people swing between hypothyroid and hyperthyroid symptoms, which can feel really confusing.
Here are some of the most common ones:
- Fatigue and exhaustion
- Brain fog
- Unexplained weight gain or weight loss
- Loss of the outer third of the eyebrows
- Dry or coarse hair, or hair loss
- Constipation
- Depression or anxiety
- Nervousness or irritability
- Increased sweating
- Heart racing or palpitations
- Hand tremors
- Muscle cramps or weakness, especially in the upper arms and thighs
- Difficulty sleeping
- Low libido
- Hives or skin rashes
- Anemia
- High cholesterol
- Thinning skin
- Irregular menstrual cycles
- Water retention
- Low Vitamin D or low B12
- Excessive appetite or loss of appetite
Because symptoms vary so much, Hashimoto’s is often missed or misdiagnosed for years. If you’ve been struggling with a cluster of these symptoms and haven’t been tested for thyroid antibodies, it’s worth asking your doctor.
What Causes Hashimoto’s Disease?
This is the big question, right? And the honest answer is: there is rarely just one cause. In my years of working with clients who have Hashimoto’s, I’ve found that there are always multiple root causes happening at the same time. It’s not as simple as pointing to one thing.
Here are the most common root causes I see:
1. Stress – Please don’t skip past this one. Stress comes in many forms, and it is almost always a factor when it comes to autoimmune disease.
Here are the different kinds of stress that can affect your immune system:
- Mental stress: being overworked, being in a hurry constantly, having too much on your plate, or trying to do too many things at once
- Emotional stress: depression, anxiety, anger, feeling overwhelmed, or not having enough joy in your life
- Physical stress: too much exercise, not enough sleep, or a physical injury like a concussion or broken bone
- Chronic illness: constantly getting sick with things like bronchitis, the flu, sinus infections, or allergies
- Chronic disease: autoimmunity, heart disease, diabetes, and similar conditions
- Surgery: any kind
- A poor diet: processed foods, lots of sugar, and using food or caffeine as energy when you’re exhausted
- Environmental stress: synthetic chemicals, pollution, extreme temperatures, or unfiltered water
- Synthetic ingredients in body care and cleaning products
- Medications that cause nutrient deficiencies or other side effects
- A big change in routine: a new baby, a new job, night shift work, or moving to a new home
- Stressful life events: a car accident, a death in the family, an abusive relationship, or a major move
2. A Viral or Bacterial Infection
Past infections can trigger autoimmune responses in the body. Things like Epstein-Barr virus (EBV), hepatitis, herpes, and others have all been linked to the onset of Hashimoto’s. If you think back and notice your health started changing after a big illness, this could be a root cause worth looking into.
3. Digestive Issues and Gut Imbalances
Your gut and your immune system are deeply connected. Gut problems like leaky gut, candida overgrowth, SIBO (small intestinal bacterial overgrowth), low stomach acid, IBS, or colitis can all drive autoimmune conditions like Hashimoto’s. In my practice, gut issues show up as a root cause in every single client with Hashimoto’s.
4. Heavy Metal Toxicity
Heavy metals like mercury, lead, and arsenic can put a serious burden on the immune system. Exposure can come from your environment, your water, certain foods, amalgam (silver) dental fillings, or medications. Amalgam filling removal done incorrectly can also be a trigger.
5. Mold Exposure
Mold is more common than most people realize, and it can cause serious immune system problems. Mold exposure can happen in your home, your workplace, through food, or even in the air. If you’ve ever lived or worked in a building with water damage, mold is worth investigating.
6. Radiation Exposure
This one surprises people. Radiation exposure includes things like Wi-Fi, cell phone towers, smart meters, Bluetooth, baby monitors, power lines, and dirty electricity. These are called non-ionizing radiation sources, and ongoing exposure may be a stressor on the body and immune system over time.
7. Dental Work and Infections
Amalgam fillings, root canal infections, and other dental infections can all be sources of chronic stress on the immune system. If you have a history of complicated dental work, this is another root cause worth exploring with a practitioner.
8. Nutrient Deficiencies
Your thyroid and immune system need specific nutrients to work properly. Deficiencies in Vitamin A, Vitamin D, B vitamins, essential fatty acids, iodine, tyrosine, selenium, and iron can all play a role in Hashimoto’s. These deficiencies are often brought on by chronic stress or a diet full of processed foods.
How to Figure Out Your Root Causes
One of the most helpful things you can do is sit down and write out your health history in order, from the beginning to now. This might take a week or two to do well, and that’s okay. Think back over the big events in your life and write them down with dates if you can.
Then go back through and circle the events that stand out. Ask yourself: “How did I feel when this happened?” And “Did my health start changing after this?”
When you find some key events, bring that timeline to a practitioner who can help you build the right plan for your situation. In my practice, I always find that gut issues and stress are the top two root causes, plus one or two others that are unique to each person.
How Do Conventional Doctors Treat Hashimoto’s Disease?
Most conventional doctors will prescribe thyroid hormone replacement if your thyroid hormone levels are low. But outside of that, there is no standard medical treatment for Hashimoto’s antibodies.
Many patients are told that there is nothing they can do about their antibodies, that their thyroid will eventually stop working, and that they will be on medication for life. That is what I was told, too.
But I learned that there are so many things you can do holistically to support your immune system and work on your root causes. Thyroid medication can be helpful if your thyroid hormones are low, but the medication is not designed to lower antibodies or heal the underlying problem. You can take thyroid medication AND work on your root causes at the same time.
Can Diet Help with Hashimoto’s?
Absolutely. The way I like to explain it: the food you eat gives your cells the tools they need to do their job. Your cells make up your tissues, your tissues make up your organs, and your organs make up all the systems in your body. When your cells have what they need, your whole body works better. Diet can make a massive difference when it comes to Hashimoto’s.
What Is the Best Diet for Hashimoto’s?
After more than a decade of working with Hashimoto’s clients and going through my own healing journey, here is the approach I’ve seen work best:
Foods to Eat:
- Lots of cooked vegetables
- Pastured butter and animal fats
- Zinc-rich foods
- Wild seafood and sea vegetables
- Pastured meats
- Meat stock (instead of bone broth)
- Organic, pastured eggs
- Cultured or raw/unprocessed dairy (unless you have a dairy allergy)
- Fermented vegetables
- Soaked nuts, seeds, legumes, and lentils
- Organic spices and herbs
Foods to Avoid:
- Soy
- Processed foods and sugar
- Raw goitrogenic and cruciferous vegetables
- Unsoaked nuts, seeds, legumes, and grains
- Gluten
- Processed fats and oils
- Processed dairy
- Alcohol
- Caffeine
If you’d like more detail on this, tap here to read the full post on the best diet for Hashimoto’s.
Is Hashimoto’s Curable? Can Antibodies Be Reversed?
There isn’t a cure for Hashimoto’s in the conventional sense. But that doesn’t mean nothing can be done. Hashimoto’s antibodies can go into remission, and many people including myself have experienced this.
The conventional medical world doesn’t have a treatment for antibodies, which is why doctors often tell patients there’s nothing to be done. But when you work on your root causes, support your immune system, and give your body what it needs, the immune system can calm down over time. It takes patience, but it is possible. Here’s my story of how I reversed Hashimoto’s naturally.
How Can I Learn More?
I have four great options for you, depending on where you are in your journey:
- Download my free guide with 50 of my top tips to support the thyroid and immune system naturally. I’ll also send you helpful educational emails to keep you learning.
- Take my free class, “5 Keys to Thyroid Hormone Balance.” It’s just 45 minutes and packed with things you can start using right away.
- If you’re ready for a full step-by-step plan, check out my 90-Day Thyroid Reset Program. No more piecing together random information!
- Book a one-on-one consult with me for personalized support. Here’s what working together looks like.
