Differential Diagnosis for Night Sweats, Nausea, and Fatigue

Life-Threatening Conditions to Exclude First

• The American College of Radiology recommends immediate exclusion of tuberculosis, lymphomas, and HIV infection in patients presenting with night sweats, nausea, and fatigue, as these conditions require urgent intervention 1, 2, 3

Malignancies

• The National Comprehensive Cancer Network recommends that Hodgkin Lymphoma be considered in patients with B symptoms, including fever, night sweats, and weight loss, along with fatigue and lymphadenopathy 4, 2, 3
• Non-Hodgkin Lymphomas, including diffuse large B-cell lymphoma and marginal zone lymphomas, commonly manifest with night sweats, nausea, and fatigue 2
• The National Comprehensive Cancer Network guidelines suggest that Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma be considered in patients with night sweats, fatigue, and weight loss, as these are specific indications for initiating treatment 4
• Acute Lymphoblastic Leukemia presents with constitutional symptoms, including night sweats, fatigue, and nausea, often with easy bruising or bleeding 5
• Waldenström's Macroglobulinemia frequently presents with B symptoms and warrants serum immunoglobulin level testing 2, 3

Infectious Diseases

• The American College of Radiology recommends that Tuberculosis be excluded, particularly in high-risk populations, as it presents with night sweats, weight loss, prolonged cough, hemoptysis, and fatigue 1, 3
• HIV infection must be considered, especially when accompanied by fever and weight loss 3
• Granulomatosis with Polyangiitis (GPA) presents with minor upper respiratory symptoms associated with disproportionate unwellness, fatigue, weight loss, and night sweats 6

Diagnostic Algorithm

Initial Evaluation

• The National Comprehensive Cancer Network recommends obtaining a focused history, including duration and pattern of symptoms, weight loss quantification, TB risk factors, HIV risk factors, medication review, and associated symptoms 4, 1, 2
• A physical examination must include a thorough examination of all lymphoid regions, spleen, liver, and assessment for hepatosplenomegaly 4, 2

First-Line Laboratory and Imaging Studies

• The American College of Radiology recommends ordering complete blood count with differential, tuberculosis testing, HIV testing, and comprehensive metabolic panel for all patients without an obvious clinical diagnosis 1, 4, 2, 3
• Chest radiography is recommended, and if abnormal or if high TB suspicion with normal X-ray in immunocompromised patients, CT chest with contrast should be performed 1

Additional Testing Based on Initial Results

• If lymphadenopathy is present, excisional lymph node biopsy is recommended for tissue diagnosis 2
• If Waldenström's is suspected, serum immunoglobulin levels should be tested 3
• If hepatitis risk factors are present, hepatitis B and C screening should be performed 3

Critical Pitfalls to Avoid

• The American College of Radiology warns against dismissing night sweats as benign without systematic evaluation, as tuberculosis and lymphoma remain important diagnoses 1
• Fine-needle aspiration alone is insufficient for lymphoma diagnosis; excisional biopsy is required 2
• ANCA testing for GPA has only 50% sensitivity in limited disease or after corticosteroid therapy, so negative ANCA does not exclude the diagnosis 6