warum vertrage ich keinen kaffee mehr — when to see a doctor?

Sudden coffee intolerance can stem from multiple causes. Genetically, the CYP1A2 rs762551 variant influences caffeine metabolism: slow metabolizers are more sensitive. However, genetics alone rarely explain an acute change. More common triggers include altered stomach acid, gastritis, reflux, medication interactions (e.g., antibiotics, antidepressants), hormonal shifts (pregnancy, menopause), or increased stress and poor sleep. See a doctor if symptoms are severe (palpitations, tremors, nausea, diarrhea, anxiety), appear suddenly, or accompany abdominal pain, heartburn, or blood in stool. Also seek medical advice if you have chronic digestive issues or suspect an underlying condition like IBS or liver dysfunction. A DNA test for CYP1A2 can offer insight but is not diagnostic. Evidence for genetic contribution is moderate; most cases require clinical evaluation for non-genetic causes.