What is the cause of night sweats in the absence of other constitutional symptoms?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: April 24, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

Night sweats without other constitutional symptoms require a thorough evaluation to identify the underlying cause, starting with a detailed history and physical examination, followed by initial laboratory testing including complete blood count, comprehensive metabolic panel, erythrocyte sedimentation rate, C-reactive protein, thyroid function tests, and HIV testing, as recommended by various studies 1.

Initial Evaluation

The initial evaluation should focus on identifying potential causes of night sweats, including:

  • Medication use, such as antidepressants or hormone therapies
  • Alcohol consumption
  • Menopausal status in women
  • Anxiety disorders
  • Idiopathic hyperhidrosis

Laboratory Testing

Initial laboratory testing should include:

  • Complete blood count
  • Comprehensive metabolic panel
  • Erythrocyte sedimentation rate
  • C-reactive protein
  • Thyroid function tests
  • HIV testing

Additional Testing

If the initial laboratory tests are unremarkable, consider additional testing, such as:

  • Chest X-ray to rule out pulmonary pathology
  • Tuberculosis screening with interferon-gamma release assay
  • Serum protein electrophoresis to evaluate for multiple myeloma
  • CT imaging of the chest, abdomen, and pelvis to rule out occult malignancy

Referral to Specialists

If night sweats are severe or persistent despite negative initial workup, referral to appropriate specialists, such as hematology, infectious disease, or endocrinology, may be warranted.

Treatment

Treatment should target the underlying cause when identified, but for idiopathic night sweats, moisture-wicking bedding, keeping the bedroom cool, and avoiding alcohol or spicy foods before bedtime may provide symptomatic relief, as suggested by studies 1. The most recent and highest quality study 1 emphasizes the importance of excluding active tuberculosis in cancer patients, which may also be relevant to the evaluation of night sweats in other contexts.

From the Research

Night Sweats Workup

When a patient presents with night sweats and no other constitutional symptoms, a thorough workup is necessary to determine the underlying cause.

  • The workup may include a thorough history, physical examination, and directed laboratory and radiographic studies 2.
  • Laboratory tests such as a complete blood count, purified protein derivative, human immunodeficiency virus test, thyroid-stimulating hormone test, and erythrocyte sedimentation rate evaluation may be considered 2, 3.
  • Imaging studies such as a chest radiograph, and possibly chest and abdominal computed tomographic scans may also be necessary 2, 3.
  • If the initial workup is normal, and no additional disorders are suspected, reassurance and continued monitoring are recommended 3.

Differential Diagnosis

The differential diagnosis for night sweats is broad and includes:

  • Infections such as tuberculosis and Mycobacterium bovis 2, 4
  • Malignancies such as lymphoma 2
  • Endocrine disorders such as hyperthyroidism 2, 3
  • Gastroesophageal reflux disease 2, 3
  • Obstructive sleep apnea 2
  • Medications and drugs of abuse 2
  • Menopause and mood disorders 5, 3

Clinical Reasoning

Clinical reasoning is essential in the evaluation of night sweats, as the symptom can be nonspecific and the underlying cause may not be immediately apparent 6.

  • A systematic and cost-conscious approach to the workup is necessary, taking into account the patient's history, physical examination, and laboratory and imaging results 3.
  • The clinician must use their expertise and judgment to determine the best course of action for each individual patient, as the evidence-based recommendations may not always apply 6.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Diagnosing night sweats.

American family physician, 2003

Research

Persistent Night Sweats: Diagnostic Evaluation.

American family physician, 2020

Research

A 56-Year-Old Male With Weight Loss, Night Sweats, Dyspnea, and Bladder Cancer.

Journal of investigative medicine high impact case reports, 2021

Research

Night sweats: a systematic review of the literature.

Journal of the American Board of Family Medicine : JABFM, 2012

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.