Anti-thyroid antibodies mainly include antibodies to thyroglobulin, antibodies to thyroid microsomes, and antibodies to TSH receptors. Thyroid antibodies are organ-specific and species-specific, and are typical of disease but not disease-specific. They are mainly IgG antibodies, but rarely IgA and IgM. Increased antibodies generally indicate the presence of thyroid disease, mostly inflammatory, which may be ongoing or may have occurred previously. The presence of a low titer of only one antibody is of little practical significance, as it is also seen in many other diseases and in healthy individuals, and is often measured especially in older women. If there is a persistent increase in multiple antibodies, this is a cause for concern and consultation with a specialist is recommended to clarify the condition.