When coughing, intra-abdominal pressure increases, which can put pressure on the diaphragm and abdominal muscles. This pressure can cause pain in the stomach, particularly in individuals with underlying medical conditions such as Gastroesophageal Reflux Disease (GERD), Hiatal Hernia, or Peptic Ulcer Disease. The pain may range from mild discomfort to severe and sharp, depending on the severity of the underlying condition and the force of the cough.