What is the appropriate workup for unintentional weight loss?

Workup for Unintentional Weight Loss

A comprehensive workup for unintentional weight loss should include a targeted history, physical examination, laboratory testing, and appropriate imaging studies to identify the underlying cause, which is most commonly non-malignant disease rather than cancer.

Initial Assessment

History

• Ask about duration and amount of weight loss (>5% over 6 months or >10% over any time period is significant) 1
• Assess for decreased appetite, changes in dietary intake, and eating difficulties 2
• Review medication list for drugs that may affect appetite or taste 1
• Evaluate for symptoms suggesting specific diseases:
  • GI symptoms (nausea, vomiting, diarrhea, abdominal pain) 3
  • Systemic symptoms (fever, night sweats, fatigue) 4
  • Psychological symptoms (depression, anxiety) 1
• Screen for social factors (isolation, food insecurity, financial constraints) 1

Physical Examination

• Complete physical examination with focus on:
  • Vital signs including temperature 4
  • Oral cavity examination for dental issues or lesions 1
  • Abdominal examination for masses or organomegaly 5
  • Lymph node examination 4
  • Neurological assessment for cognitive impairment 1

Laboratory Testing

First-Line Tests

• Complete blood count (CBC) 1
• Basic metabolic panel 1
• Liver function tests 1
• Thyroid function tests 1
• Inflammatory markers (C-reactive protein, erythrocyte sedimentation rate) 1
• Urinalysis 1
• Fecal occult blood testing 1

Additional Tests Based on Clinical Suspicion

• Lactate dehydrogenase and ferritin (for malignancy evaluation) 1
• Protein electrophoresis (to assess for multiple myeloma) 1
• HbA1c (for diabetes) 2
• Specific tests for malabsorption if GI symptoms present 3

Imaging Studies

Initial Imaging

• Chest radiography (to screen for pulmonary malignancy or infection) 1
• Abdominal imaging based on symptoms and initial test results 5

Additional Imaging Based on Clinical Suspicion

• CT scan of chest, abdomen, and pelvis if malignancy is suspected 5
• Upper and lower endoscopy for persistent GI symptoms or abnormal initial testing 3
• Additional targeted imaging based on specific symptomatology 5

Special Considerations

Elderly Patients

• Consider age-appropriate cancer screenings 1
• Evaluate for depression, which is a common cause in older adults 1
• Assess for social isolation and ability to prepare meals 1
• Screen for polypharmacy effects 1

When Initial Workup Is Unremarkable

• A 3-6 month observation period with regular weight monitoring is recommended 1
• Consider nutritional assessment using validated tools such as:
  • Malnutrition Universal Screening Tool (MUST) 2
  • Nutritional Risk Screening 2002 (NRS-2002) 2
  • Short Nutritional Assessment Questionnaire (SNAQ) 2

Management Approach

• Treatment should focus on addressing the underlying cause when identified 1
• Avoid routine use of appetite stimulants or high-calorie supplements without addressing the root cause 1
• Consider dietary modifications that account for patient preferences and any chewing/swallowing difficulties 1
• Address contributing medications that may affect appetite or taste 1
• Provide social support and assistance with meals when needed 1

Common Pitfalls to Avoid

• Assuming malignancy is the most common cause (non-malignant causes are actually more frequent) 3
• Pursuing extensive, invasive testing before completing basic workup 6
• Overlooking medications as potential causes 1
• Failing to consider psychological and social factors 1
• Missing gastrointestinal causes, which account for approximately 30% of cases 3