Introduction – How dangerous is that?
In medical terminology, night sweat (sweating during the night) is defined as a person’s excessive perspiration during sleep. However, occasional, light sweating is not included in this definition. One speaks of night sweat only when the person concerned wakes up soaking wet that pyjamas and/or sheets have to be changed.
This nocturnal sweating can limit the sleep of the person concerned enormously and make a sufficient recovery almost impossible. Harmless causes of night sweats are, for example, general illnesses associated with fever, such as a cold. The increased temperature can cause temporary sweating at night.
Night sweats can also occur as part of a tumor disease as part of the so-called “B-symptoms” (night sweats, fever, weight loss) and thus rarely have a malignant cause. For this reason, a physician should be consulted urgently if night sweats persist over a longer period of time. The causes for the occurrence of heavy sweating at night (night sweat) can be manifold.
In most cases, the high secretion of sweat during sleep has even completely harmless causes. If the heavy sweating at night is caused by serious illnesses, other symptoms can usually also be detected in the affected patients. The simplest and also most frequent reason for heavy sweating at night is unfavorable sleeping conditions.
Too warm comforters on hot summer nights lead to night sweats just as often as bedrooms that are too heated during the winter. In addition, heavy sweating at night also occurs after drinking alcoholic beverages in the evening. Also the mental condition can lead to an enormous increase in sweat production and secretion during the night.
In this context, stress, grief, anger and fears that are processed during sleep play a decisive role. Further quite frequently observed causes for the temporary occurrence of night sweat are simple infectious diseases. Especially in patients suffering from viral diseases like flu (or diseases with flu-like symptoms), large amounts of sweat are produced and secreted during sleep.
If an infection is behind the development of night sweat, the symptom usually disappears again after a few days. Furthermore, the occurrence of night sweat is also considered a symptom of more complicated infections. Tuberculosis, for example, in addition to a number of other symptoms, is usually accompanied by heavy night sweating.
Patients infected with the HI-Virus or those already suffering from AIDS often complain of heavy sweating at night. Furthermore, the cause of heavy night sweating can also be found in some neurological diseases. For most patients who observe the occurrence of night sweats, the family doctor is the first point of contact.
As a result, general practitioners may potentially have a malignant disease behind the symptom “night sweat”, but in the majority of cases a rather harmless reason could be found in the daily routine of the practice. Especially at the beginning and during the menopause, many women present themselves to their family doctor because of heavy night sweating (see: Sweating during the menopause). In these cases the main cause is the hormonal change within the organism.
Hormone-induced night sweating can be well treated and usually disappears completely after some time. Regulatory problems of the thyroid gland, as can be observed especially in hyperthyroidism, are often accompanied by heavy sweating during the day and at night. Night sweating is also considered a typical symptom in the presence of diabetes mellitus.
Heavy night sweating is also a common phenomenon in patients suffering from an autoimmune disease. Especially those patients suffering from rheumatoid arthritis or vascular diseases such as Wegener’s granulomatosis or temporal arteritis frequently report the occurrence of night sweat. Heavy sweating at night, which is accompanied by fever and significant weight loss, should be taken particularly seriously.
With this constellation of symptoms one speaks of the so-called B-symptomatics. Although the B-symptomatics is also typical for infectious diseases such as tuberculosis and HIV, it occurs much more frequently in malignant diseases.Especially patients suffering from lymph gland cancer or leukemia develop fever, weight loss and sweating at night. However, the so-called B-symptomatics can provide a first indication of tumor diseases of any kind.
In this context, however, it should be noted that light sweating at night is not considered conspicuous. And weight loss only plays a role if it occurs without a change in dietary habits (i.e. without dieting or the like) and without an increase in physical activity. In those cases in which heavy sweating at night occurs without any detectable disease or hormonal cause, one speaks of so-called idiopathic night sweating.
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