From the Guidelines
The workup for nocturnal diaphoresis (night sweats) should begin with a thorough history and physical examination to identify potential causes, followed by initial evaluation with a complete blood count, comprehensive metabolic panel, erythrocyte sedimentation rate, and C-reactive protein to screen for infections, malignancies, and inflammatory conditions, as recommended by recent guidelines 1. The initial evaluation should also include thyroid function tests (TSH, free T4) to rule out hyperthyroidism, and for patients with fever or other concerning symptoms, blood cultures may be warranted.
- A chest X-ray should be obtained to evaluate for tuberculosis, lymphoma, or other pulmonary pathologies.
- Women of appropriate age should be asked about menopausal symptoms, as night sweats are common during perimenopause and menopause.
- Additional testing may include HIV screening, purified protein derivative (PPD) test for tuberculosis, and specific hormone levels if endocrine disorders are suspected.
- If initial testing is unrevealing but symptoms persist, consider referral for specialized testing such as CT scans or bone marrow biopsy to evaluate for lymphoma or other malignancies, as suggested by the European Organisation for Research and Treatment of Cancer/Lymphoma Study Association and the German Hodgkin Study Group definitions of limited, intermediate and advanced stages 1. It's also important to inquire about medications, as certain drugs including antidepressants, hormone therapies, and some diabetes medications can cause night sweats as a side effect, and substance use, particularly alcohol consumption before bedtime, can also trigger night sweats and should be addressed during the evaluation 1.
From the Research
Diagnostic Approach
The workup for nocturnal diaphoresis (night sweats) involves a systematic and cost-conscious strategy to identify the underlying cause. The initial step is to distinguish night sweats with or without fever 2.
Differential Diagnoses
The main differential diagnoses for night sweats include:
- Infection 2, 3, 4
- Malignancies 2, 3, 4
- Sleeping disorders 2, 3, 5
- Medication-related causes 2, 3, 4
- Menopause 3, 5
- Mood disorders 3
- Gastroesophageal reflux disease 3, 4
- Hyperthyroidism 3, 4
- Obesity 3
- Pulmonary embolism 6
Diagnostic Evaluation
A screening for infections, sleeping disorders, and a medication review are essential for every patient 2. The diagnostic evaluation may include:
- Complete blood count 3, 4
- Tuberculosis testing 3, 4
- Thyroid-stimulating hormone levels 3, 4
- HIV testing 3, 4
- C-reactive protein level 3
- Chest radiography 3, 4
- Computed tomography of the chest and/or abdomen 3, 4
- Bone marrow biopsy 2, 3, 4
- Polysomnography 3
- Additional laboratory studies if indicated 3
Management
If a clinical diagnosis is apparent based on the initial history and physical examination, specific treatment for four to eight weeks may be offered 3. If the results of the diagnostic evaluation are normal, and no additional disorders are suspected, reassurance and continued monitoring are recommended 3.