Gastroesophageal Reflux Disease (GERD): This condition is characterized by stomach acid frequently flowing back into the tube connecting the mouth and stomach (esophagus). This backwash (acid reflux) can irritate the lining of the esophagus, causing discomfort. The symptoms of stomach burning all over and cramps are common presentations of GERD, especially in a 34-year-old without other specified risk factors.

Peptic Ulcer Disease: This includes both gastric and duodenal ulcers, which can cause burning stomach pain and cramps. The pain is often localized to the upper abdomen and can be exacerbated by food.
Irritable Bowel Syndrome (IBS): While IBS is more commonly associated with changes in bowel habits, some patients may experience upper abdominal pain and cramping, which could be interpreted as stomach burning.
Food Intolerance or Allergy: Conditions such as lactose intolerance or a food allergy can lead to stomach discomfort, burning, and cramps after consuming specific foods.
Viral Gastroenteritis: Also known as the stomach flu, this can cause stomach cramps, burning, and other symptoms like diarrhea and vomiting.

Appendicitis: Although appendicitis typically presents with pain localized to the lower right abdomen, it can start as more diffuse abdominal pain, including upper abdominal discomfort. Missing this diagnosis can lead to severe consequences, including perforation and peritonitis.
Myocardial Infarction: In some cases, a heart attack can present with epigastric discomfort or a feeling of burning in the stomach area, especially in women or diabetic patients. This is a medical emergency.
Pulmonary Embolism: Similar to myocardial infarction, a pulmonary embolism can occasionally present with atypical symptoms, including epigastric pain, especially if the embolism affects the lung bases.

Zollinger-Ellison Syndrome: A rare disorder characterized by excessive gastric acid production due to a gastrin-producing tumor, leading to severe peptic ulcers and diarrhea.
Eosinophilic Gastroenteritis: A rare condition where eosinophils infiltrate the gastrointestinal tract, causing inflammation and symptoms that can include abdominal pain, nausea, and vomiting.
Gastric Cancer: Although rare in a 34-year-old, gastric cancer can present with nonspecific symptoms such as abdominal discomfort, weight loss, and difficulty swallowing.