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Is an overactive immune system causing your symptoms?

Fatigue, joint pain, and weight changes can all point to one pattern.

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May 17, 2026 3:00pm EDT

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FROM DR. BERZIN:

Autoimmune diseases like Hashimoto’s thyroiditis, rheumatoid arthritis, lupus, and celiac disease affect about 1 in 10 people, with the diagnosis often coming after flares have started seriously disrupting daily life. But with the right approach, you can get symptoms of an overactive immune system into remission sooner; it starts with knowing what to look for.

Keep reading for early warning signs and targeted antibody-level blood tests.

— Robin Berzin, MD, Founder & CEO, Parsley Health

Autoimmune conditions are most treatable before significant tissue damage has occurred. Longevity Labs includes a full autoimmune panel. Add on a visit with a board-certified clinician to interpret your results and tell you what to do next.

Check your autoimmune status

Condition Spotlight: Lupus

Lupus is a complex autoimmune condition with symptoms affecting joints, skin, hair, brain, kidneys, and energy levels. Sadly, lupus patients are often told by doctors that they aren’t actually sick, or that their illness is psychological.

One study found that almost 50% of adults with lupus are misdiagnosed at the start of their journeys.

Quick facts:

In lupus, the immune system produces autoantibodies that attack multiple organ systems simultaneously (these include the skin, joints, kidneys, and brain).
This triggers waves of systemic inflammation flares causing symptoms ranging from joint pain and fatigue to organ damage.
90% of lupus patients are women. It usually appears between ages 15 and 45.
Conventional care generally centers on suppressing immune activity during flares with anti-inflammatory and immunosuppressive medications.
Functional medicine investigates the underlying triggers driving immune dysregulation, rather than managing flares after they occur.

Looking to calm systemic immune activity before it flares? Learn more about our approach to treating Lupus and sign up for Complete Care to get started.

"I was diagnosed with Rheumatoid Arthritis and Lupus in my late 40's. Working with Dr. Chellam for over 2 years, I have improved in many areas of my RA and aging journey."
- Tammy S.

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6 Symptoms of an Overactive Immune System

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Autoimmune symptoms are easy to dismiss because they are cyclic and can overlap with other conditions or mimic natural aging processes. But you know your body, and when something feels off, it’s worth taking notice. Here are early signs you should flag.

1. Persistent fatigue. When your immune system is chronically activated, it can trigger a type of anemia that reduces oxygen delivery to tissues. This produces deep, unrelenting fatigue that rest can’t fix.

2. Joint pain or muscle aches. Beyond basic soreness, pain in your muscles or joints that migrates, fluctuates, or isn’t explained by physical activity can be an early sign of autoimmune disease.

3. Cognitive changes. Chronic immune activation affects the central nervous system directly, impairing cognitive function. This can cause distractibility, memory lapses, and brain fog.

4. Stomach pain. Some autoimmune conditions like celiac disease can cause recurring bloating, cramping, or diarrhea. Gut dysbiosis can also emerge, compounding digestive symptoms.

5. Unexplained weight gain. Stalled metabolism is a classic sign of thyroid dysregulation. As many as 1 in 8 women experience hypothyroidism, which is why we look at thyroid antibody levels in every Longevity Labs panel.

6. Skin and hair changes. Pay attention to unexplained rashes that come and go; they can indicate underlying immune hyperactivity with food sensitivities as common triggers. Hair thinning is associated with several autoimmune conditions where the immune system attacks hair follicles directly.

Studies show that autoimmune conditions are most responsive to treatment before significant tissue damage has occurred. With a targeted, root-cause approach, antibody levels can decrease, flares can become less frequent, and in many cases, symptoms can go into full remission.

In functional medicine, the goal isn't just managing what's happening now — it's protecting your health long-term.

Read more: Early Warning Signs of Autoimmune Disease

BIOMARKER SPOTLIGHT

Thyroid Peroxidase Antibodies and Thyroglobulin Antibodies

Most standard physicals look for downstream effects of autoimmune issues, meaning that levels don’t get flagged until a chronic disorder has already developed. We use TPO and TgAb to detect immune dysfunction at the earliest point and start treatment before symptoms escalate.

Thyroid Peroxidase Antibodies (TPO) measure immune system activity directed against your own thyroid. When the immune system mistakenly targets thyroid peroxidase (an enzyme central to thyroid hormone production), hormone output gets disrupted and inflammation builds in the gland. High TPO levels are most commonly associated with Hashimoto’s thyroiditis.

Thyroglobulin Antibodies (TgAb) measure a separate but related line of immune attack, this time against thyroglobulin (a protein used by the thyroid to produce and store hormones).

Why not test one or the other? Elevated TgAb can indicate active autoimmune disruption even when TPO levels seem normal — for example, some people with Hashimoto’s are TPO-negative and TgAb positive. We test both in every Longevity Labs panel to get a complete picture of your autoimmune function every time.

15 million Americans have autoimmune disease. See if your thyroid antibodies show early signs of dysfunction.

Get a full panel with TPO and TgAb

What We're Taking (and Why)

Thyroid Balance

Thyroid balance uses selenomethionine, the bioavailable form of selenium, to meaningfully reduce TPO antibody levels in people with autoimmune thyroid conditions.

The rest of the formula fills in the gaps created by chronic immune activation: iodine for thyroid hormone synthesis, zinc to protect the gland from oxidative damage, vitamins A, D, and E to support hormone signaling and antioxidant defense, and rhodiola rosea — an adaptogenic herb — to combat fatigue and stress.

Shop Thyroid Balance

“My thyroid numbers were up, I took this for a few months, and things were back to normal on my last bloodwork results.” - Melanie W.

What members are saying:

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"I was diagnosed with an aggressive form of Rheumatoid Arthritis and was told I would likely be on at least 4 medications for the rest of my life. Within 4 months of following the diet, lifestyle and supplements advised, I was completely pain free, off all medications and declared in remission! My conventional MDs declared this an unusual miracle."

- Ivy S., Parsley Health Member

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Is an overactive immune system causing your symptoms?

Fatigue, joint pain, and weight changes can all point to one pattern.

FROM DR. BERZIN:

Condition Spotlight: Lupus

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6 Symptoms of an Overactive Immune System

BIOMARKER SPOTLIGHT

Thyroid Peroxidase Antibodies and Thyroglobulin Antibodies

What We're Taking (and Why)

What members are saying:

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Further Reading

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