Have you ever found yourself sitting at your computer typing in the phrase “What does a positive ANA test result mean?” For MyLupusTeam members living with multiple conditions, this test may raise more questions than it answers.

An antinuclear antibody (ANA) test can shed some light on your lupus status — but it also helps guide the process for diagnosing several other autoimmune diseases, including Hashimoto’s thyroiditis. It’s important to note that this test can’t reveal a specific diagnosis, but it can point your doctor in the right direction.

MyLupusTeam members are curious about what an ANA test means for their lupus and overall condition. “I saw on my medical records that I’m ANA-positive — what exactly does this mean?” asked one member.

In this article, we’ll describe Hashimoto’s thyroiditis, explain how it may be connected to lupus, and consider what a positive ANA test may mean for you if you have one or both of these conditions.

What Is Hashimoto’s Thyroiditis?

Hashimoto’s thyroiditis — also known as Hashimoto’s disease — affects your thyroid, which sits at the bottom of your throat. This small, butterfly-shaped organ helps regulate your hormone levels, energy levels, and metabolism (how well your body uses food for energy).

In Hashimoto’s thyroiditis, your immune system creates proteins known as autoantibodies that your thyroid tissues, leading your immune system to attack them. This causes inflammation and damages your thyroid.

Most people with this autoimmune disease have hypothyroidism, or low levels of thyroid hormones. Without enough hormones, your body can’t function normally. In rare cases, Hashimoto’s thyroiditis may cause hyperthyroidism, or an overproduction of thyroid hormones.

The first noticeable symptom of Hashimoto’s thyroiditis is typically goiter, or an enlarged thyroid gland. You won’t feel any pain, but you’ll notice that the front of your neck looks larger than normal.

Other symptoms of this disease include:

• Extreme tiredness
• Dry skin
• A chilled feeling
• Weight gain
• Hair loss
• Constipation
• Slow heart rate
• Trouble with memory or concentration
• Puffy face and eyes
• Muscle aches and pains
• Stiff joints

How Are Hashimoto’s Thyroiditis and Lupus Related?

Lupus is another autoimmune disease that affects multiple parts of your body. The bodywide inflammation in systemic lupus erythematosus (SLE), the most common type of lupus, is also caused by your immune system attacking your healthy tissues. Commonly affected organs include the joints, skin, kidneys, and heart.

Some MyLupusTeam members have looked to others for advice on living with both lupus and Hashimoto’s thyroiditis. One member asked, “A friend of mine is in the process of being diagnosed with Hashitmoto’s. Has anyone had Hashimoto’s with lupus? Is there any advice you could give?”

Shared Risk Factors and Autoantibodies

Because both SLE and Hashimoto’s thyroiditis are autoimmune diseases, there seems to be some overlap in risk factors. Right now, no research shows that SLE causes Hashimoto’s disease or vice versa. However, Hashimoto’s seems to affect people with lupus more than the general population.

These diseases share some risk factors. For example, young women are four to 10 times more likely to develop Hashimoto’s thyroiditis compared with men, according to the National Institute of Diabetes and Digestive and Kidney Diseases. Women also account for 90 percent of lupus cases, per the Lupus Foundation Foundation of America.

Research shows that people with lupus are more likely to develop Hashimoto’s thyroiditis. This is because they have autoantibodies targeting thyroid tissues. Examples include anti-thyroperoxidase (anti-TPO), anti-thyroglobulin (anti-Tg), and anti-thyroid stimulating hormone (anti-TSH) receptor autoantibodies. A 2023 study also showed that people with Hashimoto’s are at a higher risk of developing SLE.

What Is an ANA Test?

An ANA test measures the levels of antinuclear antibodies in your bloodstream. Your immune system makes these autoantibodies, which attack components of your cells’ nuclei. The nucleus holds DNA and proteins.

Studies show that between 20 percent and 30 percent of people in the general population have these antibodies. This is because other conditions, including viral infections and cancer, can also trigger your immune system to make antinuclear antibodies. However, higher levels may be a sign of an autoimmune disorder.

Unfortunately, ANA tests can’t detect your specific autoimmune disease, but they can let your doctor know that you may have this type of condition. Your doctor can then use other tests to help narrow down potential diseases. Positive ANA tests may be used to further diagnose SLE, Hashimoto’s thyroiditis, Sjögren’s syndrome, and rheumatoid arthritis.

ANA testing typically uses a panel that measures several different antibodies. Your doctor may order testing for anti-double-stranded DNA and other DNA-related proteins. If you see any names suggesting these antibodies on your medical record, talk to your doctor about what the results mean for your diagnosis.

ANA Test for Lupus

An ANA test may be the first step in diagnosing SLE. Up to 95 percent of people with lupus have a positive ANA test, but only 11 percent to 13 percent of people who do test positive for these antibodies actually have lupus, according to the American College of Rheumatology. This means that other tests are necessary to make an official lupus diagnosis.

If you have a positive ANA test, your doctor or rheumatologist may order other tests, including:

• Complete blood count — Measures your red blood cell, white blood cell, and platelet counts
• Urinalysis — Determines how well your kidneys are working and checks for infections
• Erythrocyte sedimentation rate — Looks at how quickly your red blood cells clump together and fall to the bottom of a test tube, which indicates amount of inflammation
• Complement levels — Measures proteins from the complement system, another part of your immune system that attacks your tissues in SLE

ANA Test for Hashimoto’s Thyroiditis

Fewer studies have looked at Hashimoto’s thyroiditis because it’s a much less common disease. One small report of 154 people with autoimmune thyroid diseases (including Hashimoto’s thyroiditis and Graves’ disease) found that 17.5 percent of participants had a positive ANA test. The findings were published in the journal Medical Principles and Practice.

If you’re ANA-positive, your doctor may order other tests to help diagnose thyroid disease, including:

• TSH levels — Measures TSH, with higher levels indicating that your thyroid isn’t working properly
• Thyroid autoantibody tests — Measure levels of anti-TPO, anti-Tg, and anti-TSH receptor autoantibodies
• Free T4 test — Measures thyroid hormone in your bloodstream, with low levels indicating a thyroid problem

Talk to Your Doctor About Your ANA Test Results

If you recently had an ANA test and want to learn more about your results, talk to your doctor. It’s best not to try to interpret the results yourself — they can be confusing, and you may come to the wrong conclusion. There’s plenty of information available on the internet, but your doctor knows your health history best. They can help you better understand your ANA test results in the context of your own health.

ANA tests — in addition to other tests — can help your doctor make an accurate diagnosis and get you started on the correct treatment plan. Lupus is managed with medications that help reduce inflammation.

If you have hypothyroidism caused by Hashimoto’s thyroiditis, your doctor may prescribe lab-made or synthetic thyroid hormones. One example is levothyroxine, which replaces the thyroxine hormone your body normally makes.

Talk With Others Who Understand

MyLupusTeam is the social network for people with lupus and their loved ones. On MyLupusTeam, more than 223,000 members come together to ask questions, give advice, and share their stories with others who understand life with lupus.

Have you recently had an antinuclear antibody test? How did your doctor help you better understand the results? Share your experience in the comments below, or start a conversation by posting on your Activities page.