breath test

breath test,

any of various tests in which a person's breath is analyzed for presence of something abnormal. Subgroups called the ¹³C breath tests and ¹⁴C breath tests involve administration of organic compounds labeled with carbon 13 (heavy carbon) or carbon 14 (radioactive carbon) and measuring the subsequent levels of labeled carbon dioxide in the patient's breath; the labeled compound may be found to be metabolized normally, too fast, or too slow in the GI tract.

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breath test

Chest medicine Any of a number of clinical tests used to evaluate malabsorption, in which a food containing a substance emitting low levels of radioactivity is ingested and, if malabsorbed, is exhaled through the lungs. Cf 2H-lactose test, 14C-xylose test GI disease See Urea breath test Lab medicine The testing of gases exhaled from a Pt for the presence of volatile organic compounds–VOCs.