How do you work up a patient with nausea?

Workup of Nausea

Begin by determining if nausea is acute (≤7 days) or chronic (≥4 weeks), as this fundamentally changes your diagnostic approach and urgency of evaluation. 1, 2

Initial Assessment Framework

Acute Nausea (≤7 days)

• Most common causes require minimal workup: gastroenteritis, viral syndromes, foodborne illness, medication adverse effects, early pregnancy, acute migraine, or vestibular disturbances 2
• Check pregnancy test immediately in all women of childbearing age—this is the most common endocrinologic cause 3
• Review all medications and recent additions including opioids, chemotherapy, antibiotics, and supplements 1, 3
• Screen for alarm symptoms requiring immediate hospitalization: severe dehydration, metabolic abnormalities, surgical abdomen, or neurologic signs 3
• Basic laboratory testing only if indicated: electrolytes, renal function, liver enzymes, and glucose if dehydration or metabolic concerns exist 3

Chronic Nausea (≥4 weeks)

A systematic evaluation is mandatory as symptoms poorly predict functional versus pathological illness. 4

History Must Include:

• Timing patterns: relationship to meals, time of day, duration of episodes 1, 2
• Associated symptoms: abdominal pain location/character, weight loss, early satiety, bloating, constipation 1, 2
• Medication/toxin exposure: complete list including over-the-counter, supplements, cannabis, alcohol 1, 3
• Neurologic symptoms: headache patterns, visual changes, focal deficits (suggests increased intracranial pressure) 3
• Psychiatric history: anxiety, depression, eating disorders, somatization 5, 3

Physical Examination Focus:

• Abdominal examination: distension, tenderness, masses, succussion splash, bowel sounds 3
• Neurologic examination: papilledema, focal deficits, nystagmus 3
• Volume status: orthostatic vital signs, mucous membranes 3

Diagnostic Testing Algorithm

First-Line Testing for Chronic Nausea:

• Basic metabolic panel: electrolytes, glucose, calcium, renal function 3
• Liver function tests 3
• Thyroid-stimulating hormone 3
• Complete blood count 3
• Pregnancy test (if applicable) 3
• Plain abdominal radiographs if obstruction suspected 3

Second-Line Testing (Based on Clinical Suspicion):

• Upper endoscopy: if alarm symptoms (weight loss, dysphagia, age >50 with new onset), suspected peptic disease, or gastric outlet obstruction 3
• Gastric emptying study: if symptoms suggest gastroparesis (postprandial fullness, early satiety, bloating) 6
• CT abdomen: if mass, obstruction, or intra-abdominal pathology suspected 3
• Brain imaging (CT/MRI): if neurologic signs, severe headache, or papilledema present 3

Special Populations

Cancer Patients

Screen at every initial outpatient and inpatient visit for nausea and vomiting 5

Common causes beyond chemotherapy/radiation: 5

• Constipation or fecal impaction
• Bowel obstruction (especially colorectal and ovarian cancer)
• Brain metastases
• Hypercalcemia
• Opioid-induced gastroparesis
• Gastric outlet obstruction from tumor/liver metastases

Workup priorities: 5

• Check calcium level
• Assess for constipation/impaction
• Evaluate medication list (especially opioids, anticholinergics)
• Consider imaging if obstruction suspected
• Check drug levels if on digoxin, phenytoin, carbamazepine, tricyclics

Postoperative Patients

• Monitor for progressive ileus or gastric distension, particularly in patients with risk factors for gastrointestinal obstruction 7
• Decreased bowel activity may be masked by antiemetics 7

Common Pitfalls to Avoid

• Do not perform extensive testing for acute nausea without alarm symptoms—most cases are self-limited and resolve with symptomatic treatment 2
• Do not assume functional etiology without adequate workup—symptoms are poor predictors of pathological versus functional disease 4
• Do not overlook medication adverse effects—this is one of the most common and reversible causes 1, 3
• Do not miss pregnancy—always test before extensive workup or prescribing teratogenic medications 3
• Do not ignore neurologic symptoms—these suggest increased intracranial pressure requiring urgent imaging 3

When to Escalate Evaluation

Hospitalization required for: 3

• Severe dehydration or electrolyte abnormalities
• Suspected surgical causes (obstruction, perforation)
• Intractable vomiting despite outpatient management
• Concerning metabolic abnormalities

Consider gastroenterology referral if: 6

• Chronic symptoms without identified cause after initial workup
• Suspected gastric neuromuscular disorders
• Need for advanced testing (gastric emptying studies, manometry)