What are the causes and treatment options for night sweats?

Night Sweats: Causes and Treatment

Initial Diagnostic Approach

The most common causes of night sweats in primary care are menopause/vasomotor symptoms, mood disorders, gastroesophageal reflux disease, hyperthyroidism, and obesity—not the serious conditions like tuberculosis or lymphoma that dominate medical literature. 1

Key Historical Features to Elicit

• Duration and frequency: Persistent night sweats occurring nightly warrant more thorough evaluation 1
• Associated symptoms that suggest serious pathology: Weight loss >10%, fever, cough >2 weeks (tuberculosis risk), lymphadenopathy, or hemoptysis 2
• Medication review: Antihypertensives, antipyretics, SSRIs/SNRIs, alcohol, and opiates commonly cause night sweats 3, 2
• Menopausal status: Vasomotor symptoms affect approximately two-thirds of postmenopausal women with breast cancer history and are the most frequent hormonal cause 2, 4
• Sleep disruption patterns: Distinguish true hyperhidrosis from hot flashes; ammoniacal odor and coldness on awakening suggest emotional/psychological sweating mechanism 5

Physical Examination Priorities

• Lymph node examination: Enlarged nodes require excision or ultrasound-guided core biopsy to exclude lymphoma 2
• Thyroid examination: Hyperthyroidism is a frequent hormonal cause 1, 4
• Skin examination: Erythroderma with night sweats suggests psoriasis or cutaneous T-cell lymphoma 2

Initial Laboratory and Imaging Workup

When history and physical examination do not reveal a specific cause, proceed with this systematic approach: 1, 3

• Complete blood count with differential: Screens for polycythemia vera, lymphoma, and anemia 2, 1
• Thyroid-stimulating hormone: Rules out hyperthyroidism 6, 1
• Fasting glucose: Excludes diabetes and hypoglycemia as causes 6, 3
• Tuberculosis testing (purified protein derivative or interferon-gamma release assay): Essential in high-risk populations or those with cough >2 weeks 2, 1, 3
• HIV testing: Important screening test 1, 3
• C-reactive protein or ESR: Nonspecific inflammatory marker 1
• Chest radiograph: Screens for tuberculosis, lymphoma, and pulmonary pathology 2, 1, 3

Additional Testing When Initial Workup is Negative

• Chest/abdominal CT: Consider if clinical suspicion remains high 1, 3
• Polysomnography: If obstructive sleep apnea suspected 1, 3
• Bone marrow biopsy: Reserved for unexplained hematologic abnormalities 1, 3

Treatment Based on Etiology

Vasomotor Symptoms (Menopausal Night Sweats)

For postmenopausal women, venlafaxine 37.5-75 mg daily (extended-release) is the preferred first-line treatment, reducing hot flash frequency by 40-65% with faster onset than alternatives. 6, 7

Alternative first-line non-hormonal options include: 6, 7

• Paroxetine 7.5-12.5 mg daily (controlled-release), reducing hot flash composite score by 62-65%—avoid if taking tamoxifen due to CYP2D6 inhibition 6
• Gabapentin 300-900 mg daily, particularly useful for sleep-disrupting night sweats 6

Hormone therapy is contraindicated in women with history of breast cancer, endometrial cancer, venous thromboembolism, stroke, coronary heart disease, or active liver disease 6

Adjunctive measures: 6, 7

• Acupuncture shows equivalent or better efficacy compared to venlafaxine or gabapentin in some studies 6
• Weight loss of ≥10% may eliminate symptoms 6
• Smoking cessation improves frequency and severity 6
• Cognitive behavioral therapy reduces perceived symptom burden 7

SSRI/SNRI-Induced Night Sweats

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

Tuberculosis

For patients with cough, night sweats, fever, hemoptysis, and/or weight loss in high TB prevalence areas, initiate XpertMTB/RIF testing when available, along with chest radiograph. 2

Polycythemia Vera

If raised hemoglobin/hematocrit with microcytosis, elevated white cell or platelet count, and low ESR are present, test for JAK2 V617F mutation (present in 97% of cases). 2

Aspirin 300 mg daily effectively relieves pruritus and associated night sweats in polycythemia vera patients. 2

Lymphoma

Night sweats with weight loss, fever, and lymphadenopathy require lymph node biopsy; curative treatment of lymphoma resolves associated night sweats. 2

High-dose oral corticosteroids provide symptomatic relief during definitive treatment. 2

Coccidioidomycosis

Patients with weight loss >10%, night sweats >3 weeks, and extensive pulmonary infiltrates (>50% of one lung or bilateral) should receive fluconazole or itraconazole, particularly if complement fixation titers ≥1:32. 2

Primary Sleep Hyperhidrosis

Oxybutynin (anticholinergic) shows excellent efficacy with minimal side effects for severe primary sleep hyperhidrosis unresponsive to other measures. 5

Prognosis and Reassurance

Life expectancy of primary care patients reporting night sweats is not reduced; the symptom alone does not indicate increased mortality risk. 8, 1

If systematic evaluation reveals no serious underlying disorder after 4-8 weeks, reassurance and continued monitoring are appropriate. 1

Common Pitfalls to Avoid

• Do not assume tuberculosis or lymphoma without supporting clinical features—these are rare causes in modern primary care despite historical emphasis 8, 3
• Do not overlook medication-induced causes, particularly antihypertensives and psychotropic medications 3
• Do not prescribe hormone therapy to older postmenopausal women (age >60 or >10 years post-menopause) due to cardiovascular and dementia risks 6
• Do not use paroxetine in patients taking tamoxifen 6