Skip to main content
Your session has expired. Reloading...

Doctor's Assessment Included

Every result includes a professional assessment from a BIG-registered doctor. For treatment decisions, discuss your results with your GP.

Thyroid

TPO antibodies: the TPO antibody test for thyroid autoimmunity

TPO antibodies may signal autoimmune thyroid activity. In adults over 60, thyroid autoimmunity may have developed gradually over years. Testing can help your healthcare provider understand whether thyroid function changes are autoimmune-related and guide appropriate care.

What It Measures

This test measures antibodies against thyroid peroxidase (TPO), an enzyme essential for thyroid hormone synthesis. The presence of these antibodies may indicate that the immune system is targeting the thyroid gland. A peroxidase antibody result is considered against a laboratory reference range. A higher value does not by itself confirm a condition. A doctor reviews the test results alongside TSH and any symptoms.

Why It Matters

For older adults, thyroid autoimmunity is a common cause of hypothyroidism. TPO antibody testing may help explain symptoms like persistent fatigue, cognitive changes, or cold intolerance that might otherwise be attributed to ageing. Your healthcare provider can use this information to develop an appropriate management strategy.

When to Test

Your healthcare provider may recommend TPO antibody testing when an autoimmune thyroid condition is suspected, when TSH levels are abnormal, or when there is a family history of thyroid disease. It may also be considered during pregnancy planning, as thyroid autoimmunity can potentially affect pregnancy outcomes.

Symptoms

Low Levels

Low or undetectable TPO antibody levels are generally considered normal and typically do not cause symptoms. The absence of these antibodies may suggest that autoimmune thyroid disease is less likely. However, your healthcare provider will consider your full clinical picture when interpreting results.

High Levels

Some people with elevated TPO antibodies may experience symptoms of hypothyroidism, such as fatigue, weight gain, cold sensitivity, dry skin, or low mood. Others may remain asymptomatic for years. The presence of antibodies does not always mean thyroid dysfunction is currently present. Consult your healthcare provider for evaluation.

Recommendations

Male

If Low

Normal TPO antibodies indicate no autoimmune thyroid disease. Maintain regular thyroid monitoring.

If High

Elevated TPO antibodies indicate autoimmune thyroid disease (Hashimoto's or Graves'). Consider thyroid ultrasound and endocrinology consultation.

Female

If Low

Normal TPO antibodies indicate no autoimmune thyroid disease. Maintain regular thyroid monitoring.

If High

Elevated TPO antibodies indicate autoimmune thyroid disease (Hashimoto's or Graves'). Consider thyroid ultrasound and endocrinology consultation.

Lifestyle Tips

Some people find that an anti-inflammatory diet, stress management, adequate vitamin D and selenium intake, and regular exercise may support thyroid health when TPO antibodies are present. Avoiding excessive iodine intake is sometimes discussed. Always consult your healthcare provider before making significant dietary or lifestyle changes.

Every blood test result includes a professional assessment from a BIG-registered doctor. For treatment decisions, discuss your results with your GP.

Frequently Asked Questions

Does having TPO antibodies mean I have Hashimoto's disease?
Elevated TPO antibodies are commonly found in Hashimoto's thyroiditis, but their presence alone does not confirm the diagnosis. Some people with TPO antibodies maintain normal thyroid function for years. Your healthcare provider will consider your full clinical picture, including TSH levels, to make a diagnosis.
Can TPO antibody levels decrease over time?
TPO antibody levels may fluctuate over time. Some people may see levels change with treatment or lifestyle modifications. However, the clinical significance of these changes varies. Your healthcare provider can advise on what monitoring approach is appropriate for you.
Should TPO antibodies be tested during pregnancy?
Your healthcare provider may recommend TPO antibody testing during pregnancy or when planning pregnancy, as thyroid autoimmunity may be associated with increased risk of certain pregnancy complications. Discuss your individual situation with your healthcare provider for personalised guidance.