Why Do I Feel Nauseous After Drinking Coffee?

Coffee can trigger nausea through several mechanisms in your digestive system. Caffeine stimulates acid production in your stomach, which can cause irritation and nausea, especially on an empty stomach. Coffee may worsen nausea or other stomach symptoms in some people, but its acidity alone may not explain these effects. Caffeine also affects the nervous system and may contribute to nausea, particularly in people who are sensitive to it or consume a large amount. Some people may be more sensitive to caffeine or other compounds in coffee. Caffeine withdrawal can also cause nausea after regular caffeine use is reduced or stopped. Drinking coffee quickly or on an empty stomach may worsen nausea for some people, and larger caffeine amounts can increase side effects. Sensitivity varies, and some people should follow lower caffeine limits recommended by their clinician.