What are the causes and treatment options for night sweats?

Night Sweats: Causes and Treatment

Immediate Priority: Exclude Life-Threatening Conditions First

Begin by systematically ruling out tuberculosis, lymphoma, and HIV infection, as these require urgent intervention and are the most critical diagnoses to identify. 1, 2

Red Flag Symptom Patterns

• Classic TB triad: Persistent cough (>2-3 weeks), unintentional weight loss >10%, and night sweats together strongly suggest tuberculosis 3, 1, 4
• B symptoms: Fever, night sweats, and weight loss >10% over 6 months indicate lymphoma (Hodgkin or non-Hodgkin) 3, 1, 2
• Aquagenic pruritus (intense itching after water contact) with night sweats suggests polycythemia vera 3

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Diagnostic Algorithm

Step 1: Focused History (Critical Elements)

• Duration and pattern: Frequency, severity, and timing of night sweats 4, 2
• Constitutional symptoms: Quantify weight loss, document fever patterns, assess for persistent cough 1, 2
• TB risk factors: Prior TB exposure, contact with drug-resistant cases, residence in high-prevalence areas (>100 per 100,000), immunosuppression 3, 1, 4
• HIV risk factors: High-risk sexual behavior, injection drug use 1, 2
• Medication review: Antihypertensives, antipyretics, SSRIs, alcohol, heroin 5
• Gender-specific: Menopausal symptoms in women (46-73% of female cancer survivors experience this), androgen deprivation therapy in men (50-80% affected) 4

Step 2: Physical Examination (Specific Findings)

• Lymphadenopathy: Examine all lymphoid regions systematically—cervical, supraclavicular, axillary, inguinal 2
• Hepatosplenomegaly: Palpate for enlarged liver and spleen 2
• Signs of hyperthyroidism: Tachycardia, tremor, thyroid enlargement 6, 7

Step 3: First-Line Laboratory Testing

Order these tests for all patients without an obvious clinical diagnosis: 2, 6, 5

• Complete blood count with differential 2, 6, 5
• Tuberculosis testing: PPD or interferon-gamma release assay 1, 4, 2
• HIV testing 1, 2
• Thyroid-stimulating hormone (TSH) 6, 5
• Comprehensive metabolic panel 2
• C-reactive protein or ESR 3, 6
• Chest radiography 3, 1, 2

Step 4: Additional Testing Based on Initial Results

• If lymphadenopathy present: Excisional lymph node biopsy (NOT fine-needle aspiration—this is insufficient for lymphoma diagnosis) 1, 2
• If chest X-ray abnormal or high TB suspicion in immunocompromised: CT chest with contrast 1, 2
• If polycythemia suspected: JAK2 V617F mutation testing (present in 97% of polycythemia vera cases) 3
• If constitutional symptoms with normal initial workup: Consider CT chest/abdomen, bone marrow biopsy 6, 5
• If Waldenström's macroglobulinemia suspected: Serum immunoglobulin levels 1, 2

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Common Non-Life-Threatening Causes

Menopause (Most Common in Women)

• Affects 46-73% of female cancer survivors and is the most frequent hormonal cause 4, 7
• Associated with vaginal dryness and sexual dysfunction 4

Other Frequent Causes

• Gastroesophageal reflux disease (GERD): Responds to anti-reflux treatment 1, 6, 5
• Mood disorders: Including panic attacks 6, 7
• Hyperthyroidism: Second most common hormonal cause after menopause 6, 7
• Obesity and obstructive sleep apnea 6, 5

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Treatment Approach

For Identified Causes

• Tuberculosis: XpertMTB/RIF testing when available; treat according to drug susceptibility 3
• Lymphoma: Curative treatment resolves pruritus; high-dose oral corticosteroids for symptomatic relief during definitive treatment 3
• Polycythemia vera: Ruxolitinib (JAK1/JAK2 inhibitor) produces rapid reductions in pruritus; aspirin 300 mg daily effective for persistent pruritus 3
• Menopause: Hormone replacement therapy for appropriate candidates 1
• GERD: Anti-reflux treatment 1
• Coccidioidomycosis: Fluconazole or itraconazole if weight loss >10%, night sweats >3 weeks, or extensive infiltrates 1

For SSRI-Related Night Sweats

• Alpha-adrenergic blockers may reduce night sweats in patients taking serotonin reuptake inhibitors 8

For Terminal Cancer Patients

• Thalidomide and thioridazine may benefit some patients with refractory night sweats 8

If No Cause Identified After Complete Workup

Reassurance and continued monitoring are appropriate, as night sweats alone do not indicate increased mortality risk. 8, 6 Most primary care patients with persistent night sweats do not have serious underlying disorders 8, 6

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Critical Pitfalls to Avoid

• Never dismiss night sweats without systematic evaluation—tuberculosis and lymphoma remain important diagnoses even in low-prevalence settings 2
• Never rely on fine-needle aspiration alone for lymphadenopathy—excisional biopsy is required for lymphoma diagnosis 1, 2
• Do not assume negative ANCA excludes granulomatosis with polyangiitis—sensitivity is only 50% in limited disease or after corticosteroid therapy 2
• Do not overlook medication-induced causes—review all medications including over-the-counter and substances of abuse 5