A 48-year-old woman comes to your office to discuss excess sweating. When you inquire further, she states that she often feels flushed and has been waking up from sleep to find that her bedding is wet. The first several times it happened, she did not give it much thought, but now it is happening more frequently, and she is concerned that something may be wrong.
- How do you distinguish between night sweats and other kinds of sweating?
- What conditions are associated with night sweats, and how can the patient history guide you to the right diagnosis?
- Can you make a definite diagnosis through an open-ended history followed by focused questions, or is further testing required?
- What are the elements of the patient history that can help you to distinguish between benign causes of night sweats and more serious ones that require urgent attention?
Night sweats are a frequent complaint in the primary care setting. While most often benign, night sweats may be a manifestation of serious systemic disease and should prompt a thorough evaluation to determine the cause. Diagnosis requires a careful medical history, as well as an understanding of the epidemiology and differential diagnosis of this symptom.
Night sweats are drenching sweats that require the patient to change bedclothes. This definition emphasizes the need to distinguish “night sweats” from other conditions that may be associated with increased sweating but do not have the same nocturnal pattern or clinical implications. The causes of night sweats vary, ranging from common, typically benign conditions to serious disorders associated with significant morbidity and mortality.
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|Flushing||Acute onset of cutaneous vasodilatation with marked changes in skin color, ranging from bright red to cyanotic. Although it primarily involves the face, neck, and upper chest, it can extend to the whole body including the palms and soles.|
|Hot flashes||Autonomic symptoms associated with menopause. They are characterized by the sudden onset of intense warmth and redness in the face, chest, and upper back and may include palpitations, profuse sweating, and anxiety. These symptoms typically last only 5–15 minutes.|
|Hyperhidrosis||Troublesome, benign increase in sweating beyond that necessary to maintain thermal homeostasis.|
|Night sweats||Drenching sweats that occur during sleep and require the patient to change bedclothes. By definition, the following features must not be present: fever, excessive bedding, or increased temperature in the sleeping quarters.|
Although numerous causes of night sweats exist, determining a specific etiology can be challenging. Common causes include hormonal changes associated with pregnancy and menopause and medications, particularly antipyretic and antidepressant medications.1 Unfortunately, the literature on night sweats lacks scope, consistent nomenclature, or rigorous methodology, making an evidence-based approach difficult.