Differential Diagnosis for 19-year-old Female with Nausea, Vomiting, and Upper Stomach Symptoms

• Single most likely diagnosis:
  • Gastroesophageal reflux disease (GERD): This condition is characterized by stomach acid frequently flowing back into the tube connecting the mouth and stomach (esophagus). The symptoms of nausea, vomiting, and the sensation of a knot in the stomach can be associated with GERD, especially if the patient experiences these symptoms after eating or at night.
• Other Likely diagnoses:
  • Peptic ulcer disease: This includes both gastric and duodenal ulcers, which can cause upper stomach pain, nausea, and vomiting. The pain is often described as a burning sensation and can be relieved by eating or worsened by hunger.
  • Functional dyspepsia: Also known as non-ulcer stomach pain or indigestion, this condition causes signs and symptoms of indigestion, but no visible evidence of an ulcer or other disease in the upper digestive tract.
  • Viral gastroenteritis: Commonly known as the stomach flu, this condition can cause nausea, vomiting, and stomach cramps, although the presence of a knot in the stomach might be less typical.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
  • Appendicitis: Although the pain typically starts near the belly button and then moves to the lower right abdomen, atypical presentations can occur, especially in young women. Nausea and vomiting are common accompanying symptoms.
  • Ectopic pregnancy: This is a life-threatening condition where the embryo implants outside the uterus, often causing abdominal pain, nausea, and vomiting. A pregnancy test should be considered, especially if there's any chance the patient could be pregnant.
  • Pancreatitis: Inflammation of the pancreas can cause severe upper abdominal pain that radiates to the back, nausea, and vomiting. The pain can be constant and severe.
• Rare diagnoses:
  • Gastric cancer: Although rare in young individuals, it can present with non-specific symptoms such as nausea, vomiting, and upper abdominal discomfort.
  • Inflammatory bowel disease (IBD): Conditions like Crohn's disease and ulcerative colitis can cause a wide range of gastrointestinal symptoms, including nausea, vomiting, and abdominal pain, though they more commonly present with changes in bowel habits.
  • Porphyrias: A group of disorders that can cause abdominal pain, nausea, and vomiting, among other symptoms, due to the buildup of natural chemicals that produce porphyrin in the body.