What to watch with TSH and allergy?

The relationship between TSH and allergies is complex. TSH (thyroid-stimulating hormone) is a marker of thyroid function, not directly of allergies. However, there is mechanistic evidence for crosstalk between thyroid hormones and the immune system: hypothyroidism (elevated TSH) may be associated with increased allergic reactivity, while hyperthyroidism (low TSH) may have immunosuppressive effects. But the evidence is mostly mechanistic and not strong enough for clinical recommendations. A MyBody-X test does not measure TSH directly—it analyzes DNA variants that may be linked to thyroid function, but not current hormone levels. To understand TSH and its potential link to allergies, a blood test is required. Lifestyle, diet, and inflammation status are far more influential than single genetic variants. Caution: Do not self-treat with thyroid hormones or supplements without medical supervision. Evidence: unclear/mechanistic.