When Numbers Lie: A Case Report of Falsely Low Hemoglobin Due to Preanalytical Error Leading to Unnecessary Interventions

False laboratory values can trigger extensive and unnecessary diagnostic and therapeutic workups. We report a case of falsely diagnosed severe anemia that led to blood transfusions and a comprehensive evaluation, which included aggressive intervention as an endoscopy, before being traced back to a preanalytical sample collection error. Proper phlebotomy technique and education, clinical correlation, and sometimes confirmatory labs can help avoid scenarios like the one presented in this case report.