Differential Diagnosis for Constant Nausea without Vomiting or Diarrhea

Single Most Likely Diagnosis

• Gastroesophageal Reflux Disease (GERD): This condition is characterized by the backflow of stomach acid into the esophagus, leading to symptoms like nausea, heartburn, and discomfort. The absence of vomiting and diarrhea, along with the constant nature of the nausea, makes GERD a plausible diagnosis.

Other Likely Diagnoses

• Functional Dyspepsia: A common condition involving recurring signs and symptoms of indigestion that have no obvious cause. Symptoms can include nausea, bloating, and discomfort in the upper abdomen.
• Irritable Bowel Syndrome (IBS): Although IBS often presents with changes in bowel habits, some patients may experience nausea as a predominant symptom without significant vomiting or diarrhea.
• Medication Side Effects: Various medications, including antibiotics, pain relievers, and antidepressants, can cause nausea as a side effect.
• Pregnancy: Morning sickness, which can occur at any time of day, is a common symptom of early pregnancy and may present as constant nausea without vomiting.

Do Not Miss Diagnoses

• Appendicitis: Although typically presenting with abdominal pain, nausea, and vomiting, some cases of appendicitis may have atypical presentations, including isolated nausea.
• Pancreatitis: Inflammation of the pancreas can cause severe nausea, and while vomiting is common, it's not universal.
• Intra-abdominal or Pelvic Mass: Tumors or cysts in the abdomen or pelvis can cause nausea due to pressure effects or obstruction.
• Migraine: Some individuals with migraines may experience nausea without headache, known as abdominal migraine.

Rare Diagnoses

• Gastroparesis: A condition where the stomach takes too long to empty its contents, leading to nausea, vomiting, and feeling full after eating only a small amount of food.
• Cyclic Vomiting Syndrome: Characterized by recurrent episodes of severe nausea and vomiting, though some patients may experience nausea between episodes.
• Eating Disorders: Conditions like bulimia nervosa can lead to nausea, though typically accompanied by other symptoms like bingeing and purging behaviors.
• Neurological Disorders: Certain conditions, such as brain tumors or multiple sclerosis, can cause nausea due to increased intracranial pressure or other mechanisms.