Antibodies recognise thyroid peroxidase
Biomarker library
Thyroid Health
Anti-TPO
Anti-TPO antibodies target thyroid peroxidase, an enzyme your thyroid uses to make its hormones. They show that the immune system is attacking the thyroid.
Measured in your health assessment, with a doctor to explain your result. Book yours
Why it matters
They are the hallmark of Hashimoto's thyroiditis, the commonest cause of an underactive thyroid in the UK, and are found in most people with Graves' disease too. About 1 in 10 adults have them, often with perfectly normal thyroid function.
What a result can mean
Lower than the range
Negative or low antibodies are the normal result and make autoimmune thyroid disease less likely.
Higher than the range
Positive antibodies with a normal TSH mean a higher chance of developing an underactive thyroid over time, around 2 to 4% a year, so thyroid function is usually rechecked from time to time. They also matter in pregnancy.
What can help
There is no treatment for the antibodies themselves; the thyroid is treated only if its function changes. Women planning a pregnancy who have positive antibodies may have their thyroid checked more closely.
Read it with
NoteGeneral educational illustration. Colours, sizes and movement are simplified. This is not a scan or a simulation of your body. General information, not personal medical advice: a doctor reads your own results with your history.
Know your Anti-TPO.
Measured in your health assessment and explained by the doctor who reviews your results.