Influenza A is generally referred to as Influenza A H1N1. Influenza A H1N1 may cause stomach pain, but it is impossible to generalize because of the variability that exists in individuals. Influenza A H1N1 is an acute respiratory infection. It is mainly caused by the influenza A (H1N1) virus. This virus may cause inflammation of the digestive tract, and patients may experience abdominal pain, nausea, vomiting and other symptoms. However, due to the different conditions of individuals, some patients may not experience stomach pain, but may experience uncomfortable symptoms such as nasal congestion, runny nose, sore throat, headache and generalized weakness. If the condition is serious, patients can also be complicated by multi-organ functional damage, such as respiratory failure, infectious toxic shock, etc., with a high mortality rate. Therefore, once diagnosed with influenza A (H1N1), patients need to go to regular hospitals and actively cooperate with doctors to take relevant treatment measures.