A "York Test" refers to a home-based blood test offered by the company YorkTest, which primarily focuses on identifying food intolerances by measuring IgG antibodies in the blood, allowing individuals to identify potential trigger foods that might be causing digestive discomfort or other symptoms; it also offers a range of other health tests like thyroid function, cholesterol levels, and vitamin deficiencies, all conducted through a simple finger-prick blood sample sent to a laboratory for analysis.