From the Guidelines
The appropriate workup for a patient presenting with night sweats begins with a thorough history and physical examination to identify potential underlying causes, including medication use, recent infections, menopausal status, weight loss, fever patterns, and associated symptoms like cough or lymphadenopathy. Key history elements should include assessing for B symptoms such as fever, drenching night sweats, and unexplained weight loss > 10% over 6 months, as outlined in the ESMO clinical practice guidelines for diagnosis, treatment, and follow-up of Hodgkin lymphoma 1. Laboratory testing should include a complete blood count, comprehensive metabolic panel, erythrocyte sedimentation rate, C-reactive protein, and thyroid function tests. Additional first-line tests may include tuberculosis screening with a purified protein derivative test or interferon-gamma release assay, HIV testing, and a chest X-ray.
Depending on clinical suspicion, further testing might include blood cultures for infection, hormone levels for endocrine disorders, autoimmune markers, or specialized imaging such as CT scans or PET scans if malignancy is suspected, as recommended for staging and response assessment in lymphoma 1. Night sweats can result from various conditions including infections (tuberculosis, endocarditis, HIV), malignancies (lymphoma), endocrine disorders (hyperthyroidism, pheochromocytoma), menopause, medications (antidepressants, hormone therapy), or autoimmune diseases. The workup should be tailored to the patient's age, risk factors, and associated symptoms, as night sweats alone are nonspecific but can sometimes indicate serious underlying pathology requiring prompt diagnosis and treatment.
Some studies suggest that the evaluation of night sweats should also consider the exclusion of active tuberculosis, especially in cancer patients, through clinical history, physical examination, chest radiograph, and respiratory sampling 1. However, the most recent and highest quality study relevant to the general workup of night sweats emphasizes the importance of a comprehensive initial assessment including history, physical examination, and basic laboratory tests before proceeding to more specialized evaluations 1.
In terms of specific testing, the use of PET-CT for staging and response assessment in lymphoma is recommended if available, given its high sensitivity for bone marrow involvement, potentially obviating the need for bone marrow biopsy in these cases 1. The workup for night sweats should prioritize identifying potential life-threatening conditions while also considering the patient's quality of life and the potential impact of diagnostic tests and treatments on morbidity and mortality.
From the Research
Diagnostic Evaluation of Night Sweats
The diagnostic evaluation of night sweats involves a systematic and cost-conscious approach, considering the patient's history, physical examination, and laboratory tests.
- A thorough history and physical examination are essential to identify potential causes of night sweats, such as menopause, mood disorders, gastroesophageal reflux disease, hyperthyroidism, and obesity 2.
- If the history and physical examination do not reveal a specific cause, laboratory tests such as complete blood count, tuberculosis testing, thyroid-stimulating hormone levels, HIV testing, C-reactive protein level, and chest radiography may be considered 2, 3.
- Additional tests, including computed tomography of the chest and/or abdomen, bone marrow biopsy, polysomnography, and/or additional laboratory studies, may be selectively considered if initial results are normal or if additional disorders are suspected 2.
Potential Causes of Night Sweats
Night sweats can be caused by various conditions, including:
- Menopause 2, 4
- Malignancies, such as lymphoma 4, 3
- Infections, such as tuberculosis 2, 3 and human immunodeficiency virus 3
- Autoimmune diseases 4
- Gastroesophageal reflux disease 2, 3
- Hyperthyroidism 2, 3
- Obstructive sleep apnea 3
- Hypoglycemia 3
- Medications, such as antihypertensives and antipyretics 3
- Pulmonary embolism 5
Prognostic Implications of Night Sweats
The presence of night sweats alone does not indicate an increased risk of death 2, 6.
- Studies have shown that patients who report night sweats are not more likely to die or to die sooner than those who do not report night sweats, after controlling for age, sex, body mass index, education, and income 6.