Feelings of nausea, sweating and a need to vomit are all possible symptoms of a nervous stomach, according to WebMD. While bacteria and viruses are physical causes of these symptoms, excitement, stress and worry often cause them as well.
Emotions cause a variety of physical reactions, reports WebMD. For example, anger causes the heart rate to jump and adrenaline to course through the body. With anxiety, such symptoms as diarrhea, vomiting and nausea are all possible. People who suffer from frequent symptoms without a physical cause should find ways to manage the stresses of social anxiety, performance anxiety and other worries to ease their digestive systems and reduce the risk of cardiovascular disease or high blood pressure.