Acetaldehyde and Ethanol
Another reason why people have hangover is acetaldehyde. It is a noxious compound that gathers as a byproduct, after the processing of alcohol. Acetaldehyde are more harmful than alcohol. Accumulation of alcohol in the body causes symptoms such as headache, gastrointestinal disturbance and loss of appetite.
Nausea is a significant symptom of red wine hangover. It occurs due to irritated stomach and elevated production of stomach acid caused by the alcohol (ethanol) itself. This nausea does not only involve vomiting, it also includes elevated secretion and inflammation in the intestines. People that know their wine’s ABV are able to know how much they can safely consume before going into the red wine hangover range.