What are the causes and treatment options for night sweats?

Night Sweats: Causes and Treatment

Primary Diagnostic Approach

When evaluating night sweats in primary care, immediately exclude life-threatening causes—tuberculosis, lymphoma, and HIV—before considering benign etiologies, as these conditions require urgent intervention and are the most critical diagnoses despite being less common. 1, 2

Initial Risk Stratification

The presence of "B symptoms" (fever, unintentional weight loss >10% over 6 months, and night sweats) dramatically increases suspicion for serious disease and mandates aggressive workup 1, 2. Specifically assess for:

• Duration and pattern: Persistent symptoms >2-3 weeks warrant investigation 3
• Weight loss quantification: >10% body weight loss is particularly concerning 3, 2
• Associated symptoms: Cough, hemoptysis, lymphadenopathy, or hepatosplenomegaly 3, 1
• TB risk factors: Prior TB history, contact with drug-resistant cases, residence in high-prevalence areas, or HIV status 3, 4

Life-Threatening Causes to Exclude First

Tuberculosis

TB remains the most critical infectious diagnosis, presenting with night sweats, persistent cough (>2 weeks), weight loss, and hemoptysis 3, 1, 4. In high TB prevalence populations, cough with fever, night sweats, hemoptysis, and/or weight loss increases likelihood of pulmonary TB 3.

Malignancies

• Hodgkin Lymphoma: Classic presentation with B symptoms requires excisional lymph node biopsy for tissue diagnosis—fine-needle aspiration is insufficient 1, 2
• Non-Hodgkin Lymphomas: Including diffuse large B-cell and marginal zone lymphomas 2
• Waldenström's Macroglobulinemia: Night sweats are a specific indication for initiating therapy; requires serum immunoglobulin testing 1, 2

HIV Infection

Must be considered, especially with associated fever and weight loss 1, 2, 4

First-Line Diagnostic Workup

For all patients without an obvious clinical diagnosis, order the following mandatory tests: 2, 5

• Complete blood count with differential
• Tuberculin skin test or interferon-gamma release assay
• HIV testing
• Thyroid-stimulating hormone
• Comprehensive metabolic panel
• C-reactive protein
• Chest radiography

If chest X-ray is abnormal or TB suspicion is high in immunocompromised patients with normal X-ray, proceed to CT chest with contrast. 2

Additional Selective Testing

• If lymphadenopathy present: Excisional lymph node biopsy (not fine-needle aspiration) 2
• If hepatitis risk factors: Hepatitis B and C screening 1
• If Waldenström's suspected: Serum immunoglobulin levels 1, 2
• If TB suspected: XpertMTB/RIF testing when available, sputum microscopy, and chest X-ray 3

Common Benign Causes (After Exclusion of Serious Disease)

Menopause and Hormonal States

Menopause is the most frequent hormonal cause, affecting 46-73% of female cancer survivors and 50-80% of men on androgen deprivation therapy 4, 6. Vasomotor symptoms include hot flashes (recurrent episodes of flushing, perspiration, warmth sensation) and night sweats (hot flashes with perspiration during sleep) 3.

For postmenopausal women with rheumatic/musculoskeletal disease without SLE or positive antiphospholipid antibodies who have severe vasomotor symptoms and no contraindications, use HRT according to general postmenopausal population guidelines. 3

Other Common Causes

• Hyperthyroidism: Check TSH in all patients 5, 6
• Gastroesophageal reflux disease 5, 7
• Mood disorders and panic attacks 5, 6
• Obstructive sleep apnea 7
• Obesity 5
• Medications: Antihypertensives, antipyretics, serotonin reuptake inhibitors, alcohol 8, 7

Treatment Approach

For Identified Causes

If a specific clinical diagnosis is apparent after initial evaluation, offer targeted treatment for 4-8 weeks. 5

• Menopause: HRT for severe symptoms without contraindications (avoid in antiphospholipid syndrome or active thrombotic disease) 3
• SSRI-related night sweats: Alpha-adrenergic blockers may reduce symptoms 8
• Coccidioidomycosis: Treat with fluconazole or itraconazole if weight loss >10%, night sweats >3 weeks, or extensive infiltrates 3

For Unexplained Night Sweats

If systematic workup is negative and no additional disorders are suspected, provide reassurance and continued monitoring—night sweats alone do not indicate increased mortality risk. 5, 7

Critical Pitfalls to Avoid

• Never dismiss night sweats as benign without systematic evaluation—TB and lymphoma remain important diagnoses despite being less common in primary care 2, 8
• Do not rely on fine-needle aspiration for lymphoma diagnosis—excisional biopsy is required 2
• Recognize that prevalence estimates vary widely (10-60% depending on population), and most primary care patients do not have serious underlying disease 8, 5
• Remember that ANCA testing has only 50% sensitivity in limited disease, so negative results don't exclude granulomatosis with polyangiitis 2